Quiet PC
Encyclopedia
A quiet PC is a personal computer
that makes little noise
. Common uses for quiet PCs include video editing, sound mixing, home server
s, and home theater PC
s. A typical quiet PC uses quiet cooling and storage devices and energy-efficient parts.
Like noise, the term "quiet PC" is subjective and there is currently no standard definition for a "quiet PC". However, a general definition proposed by one site is that the sound emitted by such PCs should not exceed 30 dBA
. In addition to the average sound pressure level, the frequency spectrum and dynamics of the sound are important in determining if the sound of the computer is noticed
. Sounds with a smooth frequency spectrum (lacking audible tonal peaks), and little temporal variation are less likely to be noticed. The character and amount of other sound in the environment also affects how much sound will be noticed or masked, so a computer may be quiet with relation to a particular environment or set of users.
With the development of the home computer
, early systems such as the Commodore 64
were very low wattage and were often fanless. If there was a fan, it was a low-speed fan only used to cool the power supply, such as in the IBM PC XT.
Fan noise only started to become an issue as CPU processing power increased. Processors up to about 60 megahertz did not require anything more than a single case fan and a passive heatsink. Beyond that point, a fan would be installed over the CPU heatsink to blow air straight down onto the processor, in what is known as spot-cooling. There was no regard for where the intake air came from, or where exhaust was going. The sole purpose of the fan was to move heat from a small concentrated location under the heatsink into the larger air mass inside the computer case.
As desktop computers grew in performance, more fans were included to provide spot-cooling in many more specific locations where heat dissipation was needed, without regard to overall airflow or trying to do thermal analysis of cooling efficiency.
Computer cases often have not been designed to consider the overall airflow of the system, while spot-cooling fans only focus on cooling a specific location without regard to where the exhaust air is going. Sometimes fan airflow is not coordinated, such as with the power supply and case fans both blowing air in or sucking air out, with no other venting. This combination could lead to a system with a large number of internal spot-cooling fans that is overheating because there is poor overall airflow into and out of the case.
Initially this was not important for large industrial/commercial systems and for home computers, and systems typically operated at full power consumption all the time, with cooling systems also designed to operate at maximum cooling capacity all the time. The screensaver
for example, is an animated motion of a computer screen designed to prevent image burn-in, used at a time when computer monitors tended to stay powered on all the time, or only turned off by operation of a physical switch.
Energy conservation first started to become an issue with the development of portable computers that had limited battery power; reducing power usage directly translated into longer operation time. System noise is also a factor for laptops since the noise producing components cannot be shifted away to another location. The first low power and energy conserving CPUs were developed for use in laptops, while desktops continued to operate at fixed high power levels.
Large industrial systems such as network file servers and database servers were the last to get power conservation measures added, since their primary focus is high performance centralized operation. However, as system density and power usage increased, businesses began to recognize that server systems do not need to run at full power all the time, and there is money to be saved using a server that reduces power consumption when it is not needed. Individually the cost savings is small but for a large business with hundreds to thousands of systems, the savings can be significant.
Noise in personal computers has been increasing with rising computing power and number of transistors on a single die (integrated circuit)
. More transistors of a given size use more power, which releases more heat. Faster-rotating cooling fans are one common way to remove this heat. Also, motor rotation speed for hard disc drive (HDD) and Optical disc drive (ODD) has been rising for faster data processing with technical advances in micro motors. Faster rotation (usually measured in RPM) causes higher bearing friction, thus more noise, given the same bearing technology.
The noise issue had received widespread attention with AMD's early Athlon CPUs and Intel's Pentium 4 Prescott core CPU known for its excessive heat and bundled fan noise running on high RPM. With the introduction of Home Theatre PCs (HTPC), the excessive heat and noise problem, that had been mostly confined to the overclocking and quiet computing communities, came to the attention of the general public.
The main approaches to reducing noise problems from personal computers are:
The motherboard, CPU, and video card are major energy users in a computer. Components that need less power will be easier to cool quietly. A quiet power supply is selected to be efficient while providing enough power for the computer.
A motherboard based on a chipset
that uses less energy may be easier to cool quietly.
Many modern motherboard chipsets have hot northbridge
s (notably nForce4
), which may come with active cooling, usually a small, noisy fan.
Fanless heatsinks, such as the Zalman
ZM-NB47J, ZM-NBF47 or the Thermalright
HR-05, may be used to eliminate a noisy chipset fan.
Some motherboard manufacturers have replaced these fans by incorporating large heatsinks or heatpipe coolers, however they still require good case airflow to remove heat.
Also, motherboard voltage regulator
s often have heatsinks and may need airflow to ensure adequate cooling.
Motherboards can also produce coil noise
.
Undervolting and underclocking
generally require motherboard support.
Some motherboards can control the fan speed using software like speedfan
. Most recent motherboards have built in PWM based fan control for one or two fans.
. Intel's third revision Pentium 4
, using the "Prescott" core, was infamous for being one of the hottest-running CPUs on the market. By comparison, AMD's Athlon
series and the new Intel Core 2 perform better at lower clock speeds, and thus produce less heat.
Modern CPUs often incorporate energy saving systems
, such as Cool'n'Quiet
, LongHaul
, and SpeedStep
. These reduce the CPU clock speed
and core voltage
when the processor is idle, thus reducing heat. The heat produced by CPUs can be further reduced by undervolting, underclocking
or both.
Most modern mainstream and value CPUs are made with a lower TDP
to reduce heat, noise, and power consumption. Most of Intel's desktop Core 2 Duo processors have 65W TDPs, and AMD has newer processors with a TDP between 35W and 65W. Some processors come in special low power versions.
may be the largest power consumer in a computer. For instance, 161 watts peak power consumption for an ATI
Radeon
HD 2900 XT 512. Because of space limitations, video card coolers often use small fans running at high speeds, making them noisy.
Display options for making a quiet computer include:
For a given power supply size, more efficient supplies, such as those certified 80 plus
, generate less heat.
Selecting a power supply of appropriate wattage for the computer is important for high efficiency and minimizing heat. Power supplies are typically less efficient when lightly or heavily loaded. High wattage power supplies will typically be less efficient when lightly loaded, for instance when the computer is idle or sleeping. Most desktop computers spend most of their time lightly loaded. For example, most desktop PCs draw less than 250 watts at full load, and 200 watts or less is more typical.
Power supplies with thermally controlled fans can be made quieter by providing a cooler and/or less obstructed source of air. For instance, the power supply is in a separate compartment in the Antec P180 to keep the air supplied to the PSU cool.
The fan in a power supply can be replaced with a quieter one, although there is a risk of electric shock when doing this, and it usually voids the warranty.
Fanless power supplies are available.
The electrical coils in power supplies can produce noise which can become noticeable in a quiet PC.
Cases designed for low noise usually include reasonably quiet fans, and often come with a relatively quiet power supply.
Some cases for quiet computers incorporate heatsinks to cool components passively.
Cases that provide lots of space make it easier to quiet a PC, both by allowing for airflow and by accommodating large coolers.
P180 and Antec P150 often have ducting and partitioning within the case to optimize airflow and thermally isolate components. For example, the P180 has the PSU mounted in the bottom of the case in an isolated partition. This design feature allows cooler air to enter the PSU, reducing the necessary airflow and accordingly, the noise output of the fan. Apple has also employed this tactic in their G5 workstations in an effort to reduce noise.
Antec's Sonata is often considered by the mainstream to be one of the quietest PC cases; however, it has since been surpassed by the P180 and other more-advanced cases. Vents and ducts may easily be added to regular cases.
More obstructive fan grills increase pressure drop and lower airflow, necessitating higher fan speeds and more noise output. They also increase the turbulence of the flow, which causes some noise of its own. Cases designed to be quiet typically have wire grills or honeycombed fan grills, which perform almost as well as wire grills; both are far superior to the old style of stamped grill.
Features that facilitate neat cable management, such as brackets and space to run cables behind motherboard tray, help increase cooling efficiency.
Air filters can help to prevent dust from coating heatsinks and surfaces, thereby impeding heat transfer, making fans spin faster. However the filter itself can increase noise if it restricts airflow too much, or is not cleaned, requiring a larger or faster fan to handle the pressure drop behind the filter.
Regular cleaning of air intake filters will help to keep airflow minimally restricted and keep the interior clean.
In some cases a fine mesh intake screen is sufficient to stop most large dust particles from entering the system. These screens should be vacuumed or washed to remove dust.
to reduce noise by:
Ultra-120 were frequently used as CPU heat sinks in quiet computers.
Bearing and motor noise vary between different fan models and often between different samples of the same model.
Quiet PCs typically use larger (e.g. 120 mm) low-speed fans. Although 140 mm fans are made by some manufacturers, such as Aerocool and Yate Loon, there are very few cases or heatsinks that can use them. Fan adapters, which allow larger fans to be used in place of smaller ones, and fan brackets, like the Zalman FB123, often help when replacing small fans.
Quiet fan manufacturers include Nexus, EBM-Papst, Yate Loon and Scythe. In situations where the resistance to flow is very low, like in free-air conditions, Noctua fans also perform very well. Extensive comparative surveys have been posted by Silent PC Review and MadShrimps.
Fan control
lers can be used to slow down fans and to precisely choose fan speed. Fan controllers can produce a fixed fan speed using an inline resistor or diode, or a variable speed using a potentiometer
or Pulse Width Modulation (PWM). Resistor-based fan control feeds the fan a lower voltage, while PWM fan control rapidly cycles between feeding the fan full voltage and no voltage. PWM fan control reduces rotational speed, and is the easiest and most efficient option for motherboards which have PWM fan headers. This is because PWM fans in conjunction with the motherboard chipset obtain temperature data from Digital Temperature Sensors on the CPU itself. All PWM fans are four pin, and if plugged into a conventional three pin supply will operate at full speed just like a three pin fan.
Fans can also be plugged into the power supply's 5 volt line instead of the 12 volt line (or between the two for a potential difference of 7 volts, although this cripples the fan's speed sensing) to run them at a reduced speed. Most fans will run at 5 volts once they are spinning, but may not start reliably at less than 7 V. Some simple fan controllers will only vary the fans' supply voltage between 8 V and 12 V to avoid this problem entirely. Some fan controllers start the fan at 12 V, then drop the voltage after a few seconds.
Soft mounting fans (e.g. with rubber or silicone fan isolators) can help reduce transfer of fan vibrations to other components.
Intel has recently developed a piezoelectric fan for use in desktop PCs, which is quieter than motor fans and consumes a fraction of the power.
The most common loop order is reservoir to pump, radiator then the watercooling block and back to the reservoir. The radiator and fan efficiency has the greatest effect on the noise level and cooling efficiency but watercooling is currently the most effective and potentially quietest methods of cooling above ambient temperatures.
There is an inherent danger in the use of water around electrical equipment and leak testing the loop is always recommended before attaching any parts to the motherboard, after all loop connections have been made. The 12v DC pump can be run using batteries or a power supply making sure no power is going to any other part of the system. Because of these risks and the use of water under pressure watercooling is a greater technical challenge to set up due to the number of components and case modification usually required.
Previously, hard drives used ball bearing
motors, but these generated excessive noise when the rotational speed of the drive was increased to 5400 RPM or 7200 RPM. More recent desktop hard drives use fluid bearing
motors. The first hard drive widely reputed to be quiet was the Seagate
Barracuda ATA IV.
The smaller 2.5" form-factor hard drives generally vibrate less, are quieter, and use less power than the traditional 3.5" drives. On the other hand, they often have lower performance and less capacity, and cost more per gigabyte
.
To minimize vibrations from a hard drive being transferred to, and amplified by, the case, hard drives can be mounted with soft rubber studs, suspended with elastics or placed on soft foam or Sorbothane
. Hard disk enclosures can also help reduce drive noise. Care must be taken to ensure that the drive gets adequate cooling. Hard disk temperatures can often be monitored by SMART
software.
Solid-state drive
(SSD) storage offers faster seek times, lower power consumption, no moving parts; making it theoretically more reliable and silent. There is scope for very high capacity drives; however, they are currently extremely expensive per GB and are fairly scarce.
A few people use Compact Flash (CF) cards for storage. Because they use a slightly modified Parallel ATA (PATA) interface, a simple adapter is all that is needed to connect CF cards to function as an PATA or PC Card
hard disk. CF cards are also small, allowing SFF
PCs to be made, produce no noise, use very little power (further reducing heat output in the AC/DC conversion in the PSU), and an insignificant amount of heat. However, they are very expensive per GB
and are only available in small capacities.
There are also issues regarding the maximum number of writes to each sector; often specified as 100,000 write cycles. However, there are industrial grade cards which specify a higher number of erase cycles, and different file systems, or technologies such as Enhanced Write Filter
can reduce the writes to the card. Also, CF cards will fail gradually, so it will be easy to notice before any significant amount of data are lost, unlike the possible immediate failure of HDDs. Due to their small capacities they are easy to back up entirely, and often have 10 year or even lifetime warranties.
Windows minimization projects such as Winimize (Windows 98, less than 20MB) and Linux
projects such as Puppy Linux
mean that running an OS in small capacity, cheap compact flash card is possible. Because they have many OS components removed, they offer a smaller attack surface
for malware
to target.
The sustained transfer rate of current CF cards is a maximum of around 25 MB/s, compared to an average of around 70 MB/s for modern hard drives. However, the speed of flash memory is increasing at a faster rate than that of hard drives, and they have minimal seek times compared to hard drives, which increases the speed of loading many small files, and makes the PC seem more responsive as most operations performed by the OS include small files. Due to the fast seek times CF cards also don't show the effects of file system fragmentation
like hard drives do.
Newer CF cards support faster transfer protocols like DMA. It is possible to use a Compact Flash card for storing only information that isn't changed very often, such as music, videos and binary executables, while storing the small configuration files and other frequently modified data on a small hard drive or i-RAM.
Where a motherboard supports booting from USB
drives, they can be used in a similar fashion to CF cards to run the OS. With some Linux distributions, it is not much harder than using a CF card. As they both use flash memory
, they have the same advantages and disadvantages, however speed is limited by the USB bus.
The i-RAM is a solid-state disk which has four DIMM slots to allow regular PC RAM to be used like a disk. It is much faster than a hard disk, does not have the write cycle limitations of flash memory, however it requires power continuously in order to maintain its contents (from standby power or a battery when the system is off), uses more power than many laptop hard drives, has maximum capacity of 4 GiB, and is expensive.
All forms of affordable solid-state storage offer relatively small capacity. They can be used as main storage for tasks which do not use large amounts of data or large programs, such as web browsing or word processing. Larger files and programs can be stored on a secondary hard drive which is only accessed when needed. Keeping the OS, often accessed files, and smaller programs on a solid-state drive means that the hard drives can be powered down much of the time. Network-attached storage
, or NAS, is another alternative, allowing loud hard drives to be stored remotely.
Small USB drives or CF cards can be used to make the process of network booting easier also.
DriveSpeed, or emulated by virtual drive programs such as Daemon Tools
to eliminate their noise entirely. Notebook optical drives can be used, which tend to be quieter, however this may be because they tend to run slower (typically 24x CD speed, 8x DVD speed). Some DVD drives have a feature, commonly called Riplock
, which reduces drive noise by slowing the drive during video playback. For playback operations only 1x (or real time) speed is required.
A few laptops do not use cooling fans, for instance the Dell Latitude X1, Panasonic Toughbook W5 and T5, Fujitsu Lifebook P7120. Also, some netbooks, such as the Dell Mini 9, 10 and 12
do not have fans. The Mini 9 used SSD rather than a hard disk. The OLPC XO-1
has no internal moving parts.
monitors can produce coil noise, as can the external power supply for an LCD
monitor or the voltage converter for the monitor's backlight. LCD monitors tend to produce the least noise (whine) from when at full brightness. Reducing brightness using the video card does not introduce whine, but may reduce color accuracy. An LCD monitor with an external power supply tucked out of the way will produce less noticeable noise than one with the power supply built into the screen housing.
and daisy wheel
printers are often noisy, and soundproofed boxes or cabinets can be used to reduce the noise. Another solution is to locate the printer away from the immediate work area or in another room, especially if it can be controlled through a local area network.
Personal computer
A personal computer is any general-purpose computer whose size, capabilities, and original sales price make it useful for individuals, and which is intended to be operated directly by an end-user with no intervening computer operator...
that makes little noise
Noise
In common use, the word noise means any unwanted sound. In both analog and digital electronics, noise is random unwanted perturbation to a wanted signal; it is called noise as a generalisation of the acoustic noise heard when listening to a weak radio transmission with significant electrical noise...
. Common uses for quiet PCs include video editing, sound mixing, home server
Home server
A home server is a server located in a private residence providing services to other devices inside and/or outside the household through a home network and/or the Internet. Such services may include file and/or printer serving, media center serving, web serving, web caching, account authentication...
s, and home theater PC
Home theater PC
A Home Theater PC or Media Center appliance is a convergence device that combines some or all the capabilities of a personal computer with a software application that supports video, photo, music playback, and sometimes video recording functionality...
s. A typical quiet PC uses quiet cooling and storage devices and energy-efficient parts.
Like noise, the term "quiet PC" is subjective and there is currently no standard definition for a "quiet PC". However, a general definition proposed by one site is that the sound emitted by such PCs should not exceed 30 dBA
Sound pressure
Sound pressure or acoustic pressure is the local pressure deviation from the ambient atmospheric pressure caused by a sound wave. Sound pressure can be measured using a microphone in air and a hydrophone in water...
. In addition to the average sound pressure level, the frequency spectrum and dynamics of the sound are important in determining if the sound of the computer is noticed
Psychoacoustics
Psychoacoustics is the scientific study of sound perception. More specifically, it is the branch of science studying the psychological and physiological responses associated with sound...
. Sounds with a smooth frequency spectrum (lacking audible tonal peaks), and little temporal variation are less likely to be noticed. The character and amount of other sound in the environment also affects how much sound will be noticed or masked, so a computer may be quiet with relation to a particular environment or set of users.
History
Prior to about 1975, all computers were typically large industrial/commercial machines, often in a centralized location with a dedicated room-sized cooling system. For these systems noise was not an important issue.With the development of the home computer
Home computer
Home computers were a class of microcomputers entering the market in 1977, and becoming increasingly common during the 1980s. They were marketed to consumers as affordable and accessible computers that, for the first time, were intended for the use of a single nontechnical user...
, early systems such as the Commodore 64
Commodore 64
The Commodore 64 is an 8-bit home computer introduced by Commodore International in January 1982.Volume production started in the spring of 1982, with machines being released on to the market in August at a price of US$595...
were very low wattage and were often fanless. If there was a fan, it was a low-speed fan only used to cool the power supply, such as in the IBM PC XT.
Fan noise only started to become an issue as CPU processing power increased. Processors up to about 60 megahertz did not require anything more than a single case fan and a passive heatsink. Beyond that point, a fan would be installed over the CPU heatsink to blow air straight down onto the processor, in what is known as spot-cooling. There was no regard for where the intake air came from, or where exhaust was going. The sole purpose of the fan was to move heat from a small concentrated location under the heatsink into the larger air mass inside the computer case.
As desktop computers grew in performance, more fans were included to provide spot-cooling in many more specific locations where heat dissipation was needed, without regard to overall airflow or trying to do thermal analysis of cooling efficiency.
- Originally, video display controllers were fairly low power devices without any need for active cooling. But with the development of the 3D graphics card, it became common for the video card to have its own fan, separate from a general case/system fan. The development of 3D cards working in tandem required separate spot-cooling fans for each card.
- Multiprocessor systems such as the Pentium Pro typically needed a separate spot-cooling fan for each CPU.
Computer cases often have not been designed to consider the overall airflow of the system, while spot-cooling fans only focus on cooling a specific location without regard to where the exhaust air is going. Sometimes fan airflow is not coordinated, such as with the power supply and case fans both blowing air in or sucking air out, with no other venting. This combination could lead to a system with a large number of internal spot-cooling fans that is overheating because there is poor overall airflow into and out of the case.
The Green PC
With the developing societal interest in energy conservation, the concept of designing systems to only consume as much power as is needed at a particular moment has helped to reduce both power consumption and system noise.Initially this was not important for large industrial/commercial systems and for home computers, and systems typically operated at full power consumption all the time, with cooling systems also designed to operate at maximum cooling capacity all the time. The screensaver
Screensaver
A screensaver is a type of computer program initially designed to prevent phosphor burn-in on CRT and plasma computer monitors by blanking the screen or filling it with moving images or patterns when the computer is not in use...
for example, is an animated motion of a computer screen designed to prevent image burn-in, used at a time when computer monitors tended to stay powered on all the time, or only turned off by operation of a physical switch.
Energy conservation first started to become an issue with the development of portable computers that had limited battery power; reducing power usage directly translated into longer operation time. System noise is also a factor for laptops since the noise producing components cannot be shifted away to another location. The first low power and energy conserving CPUs were developed for use in laptops, while desktops continued to operate at fixed high power levels.
Large industrial systems such as network file servers and database servers were the last to get power conservation measures added, since their primary focus is high performance centralized operation. However, as system density and power usage increased, businesses began to recognize that server systems do not need to run at full power all the time, and there is money to be saved using a server that reduces power consumption when it is not needed. Individually the cost savings is small but for a large business with hundreds to thousands of systems, the savings can be significant.
Causes of noise
The main causes of PC noise are:- Mechanical friction noise generated by micro motors and fan bearings, as well as vibration noise from low quality chassis and improper assemblies.
- Turbulence caused by obstructions in the flow of air, such as poorly designed fan grilles and heatsinks. A lack of clearance between rotating fan blades and nearby support struts and grilles will create an audible noise, similar to how a mechanical sirenSiren (noisemaker)A siren is a loud noise making device. Most modern ones are civil defense or air raid sirens, tornado sirens, or the sirens on emergency service vehicles such as ambulances, police cars and fire trucks. There are two general types: pneumatic and electronic....
operates. As the fan blades spin, they produce a vortexVortexA vortex is a spinning, often turbulent,flow of fluid. Any spiral motion with closed streamlines is vortex flow. The motion of the fluid swirling rapidly around a center is called a vortex...
of air that trails off the edge of the blade. When the vortexes path crosses an object it may produce noise. Fan blades can be designed to reduce this problem by using special notched shapes. - Noise generated by electrical coils or transformers used in power suppliesPower supplyA power supply is a device that supplies electrical energy to one or more electric loads. The term is most commonly applied to devices that convert one form of electrical energy to another, though it may also refer to devices that convert another form of energy to electrical energy...
, motherboardMotherboardIn personal computers, a motherboard is the central printed circuit board in many modern computers and holds many of the crucial components of the system, providing connectors for other peripherals. The motherboard is sometimes alternatively known as the mainboard, system board, or, on Apple...
s, video cards or LCD monitors.
Noise in personal computers has been increasing with rising computing power and number of transistors on a single die (integrated circuit)
Die (integrated circuit)
A die in the context of integrated circuits is a small block of semiconducting material, on which a given functional circuit is fabricated.Typically, integrated circuits are produced in large batches on a single wafer of electronic-grade silicon or other semiconductor through processes such as...
. More transistors of a given size use more power, which releases more heat. Faster-rotating cooling fans are one common way to remove this heat. Also, motor rotation speed for hard disc drive (HDD) and Optical disc drive (ODD) has been rising for faster data processing with technical advances in micro motors. Faster rotation (usually measured in RPM) causes higher bearing friction, thus more noise, given the same bearing technology.
The noise issue had received widespread attention with AMD's early Athlon CPUs and Intel's Pentium 4 Prescott core CPU known for its excessive heat and bundled fan noise running on high RPM. With the introduction of Home Theatre PCs (HTPC), the excessive heat and noise problem, that had been mostly confined to the overclocking and quiet computing communities, came to the attention of the general public.
The main approaches to reducing noise problems from personal computers are:
- Reduce heat generation by using energy efficient parts - nearly all the energy used by a computer is converted into heat.
- Improve cooling - by using more efficient cooling parts and lower friction, quieter bearings.
- Use SoundproofingSoundproofingSoundproofing is any means of reducing the sound pressure with respect to a specified sound source and receptor. There are several basic approaches to reducing sound: increasing the distance between source and receiver, using noise barriers to reflect or absorb the energy of the sound waves, using...
to reduce the effects of remaining noise sources.
Noise reduction methods
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| Reducing noise with new CPU cooler. | |
Common noise reduction methods
- Replace heat sinkHeat sinkA heat sink is a term for a component or assembly that transfers heat generated within a solid material to a fluid medium, such as air or a liquid. Examples of heat sinks are the heat exchangers used in refrigeration and air conditioning systems and the radiator in a car...
s with more efficient models. This often entails the use of larger copper or aluminum heat sinks which may incorporate heat pipeHeat pipeA heat pipe or heat pin is a heat-transfer device that combines the principles of both thermal conductivity and phase transition to efficiently manage the transfer of heat between two solid interfaces....
s. - Replace fans with passive cooling solutions where possible, such as fans on motherboards and GPUs.
- Replace fans with low-speed, large-diameter fans with low bearing and motor noise. Larger fans can move more air per revolution than smaller fans.
- Replace the constant-speed fan in the power supplyPower supplyA power supply is a device that supplies electrical energy to one or more electric loads. The term is most commonly applied to devices that convert one form of electrical energy to another, though it may also refer to devices that convert another form of energy to electrical energy...
with a thermostatically controlled variable speed fan that runs at less than maximum speed, and thus runs quieter most of the time. - Replace the power supplyPower supplyA power supply is a device that supplies electrical energy to one or more electric loads. The term is most commonly applied to devices that convert one form of electrical energy to another, though it may also refer to devices that convert another form of energy to electrical energy...
with a quieter model. The main considerations, from a noise-reduction point of view, in choosing a power supply are fan quality, AC/DC conversion efficiency, and how good the thermal fan speed control is at keeping the fan running slow and steady. Efficiency is important because the less heat that is produced the less work the fan has to perform. - Replace hard drives with quieter models. Hard drives can also be replaced with laptop hard drives, with solid state devices like compact flash or networked file systems like NFS. This reduces or eliminates this source of noise and reduces system power and cooling requirements.
- Place a damping material around hard drives (or other spinning drives) such as SorbothaneSorbothaneSorbothane is the brand name of a synthetic viscoelastic urethane polymer used as a shock absorber and vibration damper. It is manufactured by Sorbothane, Inc., based in Kent, Ohio.Sorbothane was invented and patented in 1982 by Dr. Maurice Hiles...
- Cover the case with sound insulationSoundproofingSoundproofing is any means of reducing the sound pressure with respect to a specified sound source and receptor. There are several basic approaches to reducing sound: increasing the distance between source and receiver, using noise barriers to reflect or absorb the energy of the sound waves, using...
material such as rubber, foam or fiber mat, although this method has limited effectiveness. The material can (because of its weight) dampen case resonance, and can also absorb some high-frequency sound. Care must be taken to be sure the soundproofing does not interfere with airflow and cooling. - In energy-hungry computers, water cooling may be necessary for quiet operation. Older water pumps sometimes can make systems noisier than air-cooled, low-power computers. However, recent advances in 12v DC pump technologies have resulted in highly reduced noise levels from many pumps. In a modern watercooling system geared towards silence rather than performance, the loudest component in the computer is often the Hard Drive or Optical disc drive when performing accesses to the media.
Low-cost methods
A number of methods exist for reducing computer noise at little or no added cost.- Reduce CPU supply voltageDynamic voltage scalingDynamic voltage scaling is a power management technique in computer architecture, where the voltage used in a component is increased or decreased, depending upon circumstances. Dynamic voltage scaling to increase voltage is known as overvolting; dynamic voltage scaling to decrease voltage is known...
("undervolting"). Many of today's CPUs can run stably at their stock speed, or even with a slight overclock, at a reduced voltage, which reduces heat output. UnderclockingUnderclockingUnderclocking, also known as downclocking, is the practice of modifying a synchronous circuit's timing settings to run at a lower clock rate than it was specified to operate at. It may be said to be the computer equivalent of driving a car below the speed limit...
can be done for the same effect, however this reduces performance and is not as effective as undervolting; all the same, underclocking may allow further undervolting. Power consumption is approximately proportional to V2·f, that is, it varies linearly with the clock frequency and quadratically with the voltage. This means that even a small reduction in voltage can have a large effect in power consumption. Undervolting and underclocking can also be used with chipsetChipsetA chipset, PC chipset, or chip set refers to a group of integrated circuits, or chips, that are designed to work together. They are usually marketed as a single product.- Computers :...
s and GPUs. - Enable Cool'n'QuietCool'n'QuietCool'n'Quiet is a CPU speed throttling and power saving technology introduced by AMD with its Athlon 64 processor line. It works by reducing the processor's clock rate and voltage when the processor is idle. The aim of this technology is to reduce overall power consumption and lower heat...
for AMD CPUs or EIST on Intel's CPUs. - Reduce fan speed. For newer computers, the speed of fans can be varied automatically, depending on how hot certain parts of the computer get. Lowering a DC fan motor's supply voltage will reduce its speed while making it quieter and lowering the amount of air the fan moves. Doing this arbitrarily could lead to components overheating; therefore, whenever performing hardware work it is advised to monitor the temperature of system components. Fans with MolexMolexMolex is a leading global supplier of electronic interconnectors. Molex sells over 100,000 products, including everything from electrical and fiber optic interconnect solutions to switches and application tooling....
connectors can be modified easily. With 3-pin fans, either fixed inline resistorResistorA linear resistor is a linear, passive two-terminal electrical component that implements electrical resistance as a circuit element.The current through a resistor is in direct proportion to the voltage across the resistor's terminals. Thus, the ratio of the voltage applied across a resistor's...
s or diodeDiodeIn electronics, a diode is a type of two-terminal electronic component with a nonlinear current–voltage characteristic. A semiconductor diode, the most common type today, is a crystalline piece of semiconductor material connected to two electrical terminals...
s, or commercial fan controlFan controlFan control is the management of the rotational speed of an electric fan. There are many types of electric fans and many types of fan controls. This article principally describes the control of a computer fan, to provide adequate cooling while lowering noise....
lers, such as the ZalmanZalmanZalman Tech Co. is a Korean company that develops and provides aftermarket desktop computer products with primary focus on cooling enhancement....
Fanmate, can be used. Software like speedfanSpeedFanSpeedFan is software that can read temperatures, voltages and fan speeds of computer components. It can change computer fan speeds depending on the temperature of various components....
may allow fan speed control. Many newer motherboards support Pulse-width modulationPulse-width modulationPulse-width modulation , or pulse-duration modulation , is a commonly used technique for controlling power to inertial electrical devices, made practical by modern electronic power switches....
(PWM) control, allowing the fan speed to be set in the BIOSBIOSIn IBM PC compatible computers, the basic input/output system , also known as the System BIOS or ROM BIOS , is a de facto standard defining a firmware interface....
or with software. - Mount fans on anti-vibration mounts.
- Remove restrictive fan grills to allow easier airflow, or replace noisy fan grills with quieter versions.
- Use software such as NeroNero AGNero is a global computer software company headquartered in Karlsbad, Germany. It is perhaps most well-known for its burning software, Nero Burning ROM.-History:The company was founded as Ahead Software GmbH in 1995 by Richard Lesser....
DriveSpeed to reduce the speed of optical drives. - Isolate hard disk noise, either by using anti-vibration mounts (generally rubber or silicone grommets), or by suspending the hard disk to fully decouple it from the computer chassis by mounting it in a 5.25 inch drive bayDrive bayA drive bay is a standard-sized area for adding hardware to a computer. Most drive bays are fixed to the inside of a case, but some can be removed....
with viscoelastic polymer mounts. - Set the hard disk's AAMAutomatic Acoustic ManagementAutomatic acoustic management is a method for reducing acoustic emanations in AT Attachment mass storage devices, such as ATA hard disk drives and ATAPI optical disc drives...
value to its lowest setting. This reduces the seek noise produced by the hard drive, but also reduces performance slightly. - Set operating system to spin down hard drives after a short time of inactivity. This may reduce a drive's life span and commonly conflicts with the OS and running programs, though it can still be useful for drives that are only used for data storage.
- Defragment the hard drives to reduce the drive heads' need to search widely for data, also improves performance.
- Arrange components and cables to improve airflow. Wires hanging inside the computer can block the airflow, which can increase the temperature. They can be easily moved to the side of the case so that air can pass through more easily
- Remove dust from inside the computer. Dust on computer parts will retain more heat. Fans draw in dust along with outside air, it can build up quickly inside the computer. Dust can be removed with a vacuum cleaner, gas duster or compressed air. Special anti-static vacuum cleaners should be used however to prevent electrostatic dischargeElectrostatic dischargeElectrostatic discharge is a serious issue in solid state electronics, such as integrated circuits. Integrated circuits are made from semiconductor materials such as silicon and insulating materials such as silicon dioxide...
(ESD). Ideally, this would be done often enough to prevent a significant amount of dust from ever building up. How frequently this would need to be performed would depend entirely on the environment in which the computer is used.
Sound power and pressure measurement
Though standards do exist for measuring and reporting sound power output by such things as computer components, they are often ignored. Many manufacturers do not give sound power measurements. Some report sound pressure measurements, but those that do often do not specify how sound pressure measurements were taken. Even such basic information as measurement distance is rarely reported. Without knowing how it was measured, it is not possible to verify these claims, and comparisons between such measurements (e.g. for product selection) are meaningless. Comparative reviews, which test several devices under the same conditions are more useful. Although even then, an average sound pressure level is only one factor in determining which components will be perceived as quieter.Individual components in a quiet PC
The following are notes regarding individual components in quiet PCs.The motherboard, CPU, and video card are major energy users in a computer. Components that need less power will be easier to cool quietly. A quiet power supply is selected to be efficient while providing enough power for the computer.
Motherboards
Chipset
A chipset, PC chipset, or chip set refers to a group of integrated circuits, or chips, that are designed to work together. They are usually marketed as a single product.- Computers :...
that uses less energy may be easier to cool quietly.
Many modern motherboard chipsets have hot northbridge
Northbridge (computing)
The northbridge has historically been one of the two chips in the core logic chipset on a PC motherboard, the other being the southbridge. Increasingly these functions have migrated to the CPU chip itself, beginning with memory and graphics controllers. For Intel Sandy Bridge and AMD Fusion...
s (notably nForce4
NForce4
The nForce4 is a motherboard chipset released by Nvidia in October, 2004. The chipset supports AMD 64-bit processors and Intel Pentium 4 LGA 775 processors.-nForce4/nForce4-4x:...
), which may come with active cooling, usually a small, noisy fan.
Fanless heatsinks, such as the Zalman
Zalman
Zalman Tech Co. is a Korean company that develops and provides aftermarket desktop computer products with primary focus on cooling enhancement....
ZM-NB47J, ZM-NBF47 or the Thermalright
Thermalright
Thermalright is a Taiwan-based company that manufactures high-quality, high-performance aftermarket heat sinks for desktop computers. Thermalright products are primarily marketed towards gamer and enthusiasts who commonly overclock different parts of their computer, generating large amounts of...
HR-05, may be used to eliminate a noisy chipset fan.
Some motherboard manufacturers have replaced these fans by incorporating large heatsinks or heatpipe coolers, however they still require good case airflow to remove heat.
Also, motherboard voltage regulator
Voltage regulator
A voltage regulator is an electrical regulator designed to automatically maintain a constant voltage level. A voltage regulator may be a simple "feed-forward" design or may include negative feedback control loops. It may use an electromechanical mechanism, or electronic components...
s often have heatsinks and may need airflow to ensure adequate cooling.
Motherboards can also produce coil noise
Coil Noise
Coil Noise is a phenomenon in electronics which produces both undesirable audible sound, and electronic noise.-Description:Coil Noise is, as its name suggests, caused by Electromagnetic coils...
.
Undervolting and underclocking
Underclocking
Underclocking, also known as downclocking, is the practice of modifying a synchronous circuit's timing settings to run at a lower clock rate than it was specified to operate at. It may be said to be the computer equivalent of driving a car below the speed limit...
generally require motherboard support.
Some motherboards can control the fan speed using software like speedfan
SpeedFan
SpeedFan is software that can read temperatures, voltages and fan speeds of computer components. It can change computer fan speeds depending on the temperature of various components....
. Most recent motherboards have built in PWM based fan control for one or two fans.
CPUs
The heat output of a CPU can vary according to its brand and model - to be exact, its TDPThermal Design Power
The thermal design power , sometimes called thermal design point, refers to the maximum amount of power the cooling system in a computer is required to dissipate. For example, a laptop's CPU cooling system may be designed for a 20 watt TDP, which means that it can dissipate up to 20 watts of heat...
. Intel's third revision Pentium 4
Pentium 4
Pentium 4 was a line of single-core desktop and laptop central processing units , introduced by Intel on November 20, 2000 and shipped through August 8, 2008. They had a 7th-generation x86 microarchitecture, called NetBurst, which was the company's first all-new design since the introduction of the...
, using the "Prescott" core, was infamous for being one of the hottest-running CPUs on the market. By comparison, AMD's Athlon
Athlon
Athlon is the brand name applied to a series of x86-compatible microprocessors designed and manufactured by Advanced Micro Devices . The original Athlon was the first seventh-generation x86 processor and, in a first, retained the initial performance lead it had over Intel's competing processors...
series and the new Intel Core 2 perform better at lower clock speeds, and thus produce less heat.
Modern CPUs often incorporate energy saving systems
Power management
Power management is a feature of some electrical appliances, especially copiers, computers and computer peripherals such as monitors and printers, that turns off the power or switches the system to a low-power state when inactive. In computing this is known as PC power management and is built...
, such as Cool'n'Quiet
Cool'n'Quiet
Cool'n'Quiet is a CPU speed throttling and power saving technology introduced by AMD with its Athlon 64 processor line. It works by reducing the processor's clock rate and voltage when the processor is idle. The aim of this technology is to reduce overall power consumption and lower heat...
, LongHaul
LongHaul
VIA LongHaul is a CPU speed throttling and power saving technology developed by VIA Technologies. By executing specialized instructions, software can exercise fine control on the bus-to-core frequency ratio and CPU core voltage. When the system first boots, the ratio and voltage are set to...
, and SpeedStep
SpeedStep
SpeedStep is a trademark for a series of dynamic frequency scaling technologies built into some Intel microprocessors that allow the clock speed of the processor to be dynamically changed by software...
. These reduce the CPU clock speed
Clock rate
The clock rate typically refers to the frequency that a CPU is running at.For example, a crystal oscillator frequency reference typically is synonymous with a fixed sinusoidal waveform, a clock rate is that frequency reference translated by electronic circuitry into a corresponding square wave...
and core voltage
CPU core voltage
The CPU core voltage is the power supply voltage supplied to the CPU , GPU, or other device containing a processing core...
when the processor is idle, thus reducing heat. The heat produced by CPUs can be further reduced by undervolting, underclocking
Underclocking
Underclocking, also known as downclocking, is the practice of modifying a synchronous circuit's timing settings to run at a lower clock rate than it was specified to operate at. It may be said to be the computer equivalent of driving a car below the speed limit...
or both.
Most modern mainstream and value CPUs are made with a lower TDP
Thermal Design Power
The thermal design power , sometimes called thermal design point, refers to the maximum amount of power the cooling system in a computer is required to dissipate. For example, a laptop's CPU cooling system may be designed for a 20 watt TDP, which means that it can dissipate up to 20 watts of heat...
to reduce heat, noise, and power consumption. Most of Intel's desktop Core 2 Duo processors have 65W TDPs, and AMD has newer processors with a TDP between 35W and 65W. Some processors come in special low power versions.
Modern low power CPUs
Maximum TDP:- AMD FusionAMD FusionAMD Fusion is the marketing name for a series of APUs by AMD. There are two flavors of Fusion currently available, one with its CPU logic based on the Bobcat core and the other its CPU logic based on the 10h core. In both cases the GPU logic is HD6xxx, which itself is based on the mobile variant of...
C and E-series: 9W-18W - Athlon 64 X2Athlon 64 X2The Athlon 64 X2 is the first dual-core desktop CPU designed by AMD. It was designed from scratch as native dual-core by using an already multi-CPU enabled Athlon 64, joining it with another functional core on one die, and connecting both via a shared dual-channel memory controller/north bridge and...
: 45W, 65W, 85W - Intel CoreIntel CoreYonah was the code name for Intel's first generation of 65 nm process mobile microprocessors, based on the Banias/Dothan-core Pentium M microarchitecture. SIMD performance has been improved through the addition of SSE3 instructions and improvements to SSE and SSE2 implementations, while integer...
and Core 2 series: 35W, 65W, 85W - Intel Pentium MPentium MThe Pentium M brand refers to a family of mobile single-core x86 microprocessors introduced in March 2003 , and forming a part of the Intel Carmel notebook platform under the then new Centrino brand...
and Celeron M (lacks SpeedStep) - Intel Xeon L55xx and L56xx series: 60W
- VIA C7VIA C7The VIA C7 is an x86 central processing unit designed by Centaur Technology and sold by VIA Technologies.- Product history :The C7 delivers a number of improvements to the older VIA C3 cores but is nearly identical to the latest VIA C3 Nehemiah core. The C7 was officially launched in May 2005,...
: 12W-20W (Fanless) - transmetaTransmetaTransmeta Corporation was a US-based corporation that licensed low power semiconductor intellectual property. Transmeta originally produced very long instruction word code morphing microprocessors, with a focus on reducing power consumption in electronic devices. It was founded in 1995 by Bob...
processors - Geode (processor)Geode (processor)Geode is a series of x86-compatible system-on-a-chip microprocessors and I/O companions produced by AMD, targeted at the embedded computing market....
: 5W, 25W - Intel AtomIntel AtomIntel Atom is the brand name for a line of ultra-low-voltage x86 and x86-64 CPUs from Intel, designed in 45 nm CMOS and used mainly in netbooks, nettops, embedded application ranging from health care to advanced robotics and Mobile Internet devices...
: 2W, 4W, 8W - Loongson: 1W, 5W, 7W (Fanless)
Video cards
Video cards can produce a significant amount of heat. A fast GPUGraphics processing unit
A graphics processing unit or GPU is a specialized circuit designed to rapidly manipulate and alter memory in such a way so as to accelerate the building of images in a frame buffer intended for output to a display...
may be the largest power consumer in a computer. For instance, 161 watts peak power consumption for an ATI
ATI Technologies
ATI Technologies Inc. was a semiconductor technology corporation based in Markham, Ontario, Canada, that specialized in the development of graphics processing units and chipsets. Founded in 1985 as Array Technologies Inc., the company was listed publicly in 1993 and was acquired by Advanced Micro...
Radeon
Radeon
Radeon is a brand of graphics processing units and random access memory produced by Advanced Micro Devices , first launched in 2000 by ATI Technologies, which was acquired by AMD in 2006. Radeon is the successor to the Rage line. There are four different groups, which can be differentiated by...
HD 2900 XT 512. Because of space limitations, video card coolers often use small fans running at high speeds, making them noisy.
Display options for making a quiet computer include:
- Use motherboard video output - typically motherboard video takes less power than an external video card, typically at the price of lower gaming or HD video decoding performance.
- Select a video card that does not use a fan
- many of the more efficient GPUs are available in fanless models
- many older video cards used less power than more recent video cards, thus heatsinks or fans were often not required
- Replace the GPU cooler with a larger heatsink and possibly a larger, slower fan
- No video card - use a terminal, thin clientThin clientA thin client is a computer or a computer program which depends heavily on some other computer to fulfill its traditional computational roles. This stands in contrast to the traditional fat client, a computer designed to take on these roles by itself...
, USB display or desktop sharingDesktop sharingDesktop sharing is a common name for technologies and products that allow remote access and remote collaboration on a person's computer desktop through a graphical Terminal emulator.The most common two scenarios for desktop sharing are:* Remote log-in...
software if display required
Power supplies
PSUs are made quieter through the use of higher efficiency (which reduces waste heat and need for airflow), quieter fans, more intelligent fan controllers (ones for which the correlation between temperature and fan speed is more complex than linear), more effective heatsinks and through designs which allow air to flow through with less resistance.For a given power supply size, more efficient supplies, such as those certified 80 plus
80 PLUS
80 PLUS is an initiative to promote energy efficiency in computer power supply units . It certifies products that have more than 80% energy efficiency at 20%, 50% and 100% of rated load, and a power factor of 0.9 or greater at 100% load....
, generate less heat.
Selecting a power supply of appropriate wattage for the computer is important for high efficiency and minimizing heat. Power supplies are typically less efficient when lightly or heavily loaded. High wattage power supplies will typically be less efficient when lightly loaded, for instance when the computer is idle or sleeping. Most desktop computers spend most of their time lightly loaded. For example, most desktop PCs draw less than 250 watts at full load, and 200 watts or less is more typical.
Power supplies with thermally controlled fans can be made quieter by providing a cooler and/or less obstructed source of air. For instance, the power supply is in a separate compartment in the Antec P180 to keep the air supplied to the PSU cool.
The fan in a power supply can be replaced with a quieter one, although there is a risk of electric shock when doing this, and it usually voids the warranty.
Fanless power supplies are available.
- Some of them are equipped with large passive heat sinks and rely on convection or case airflow to dissipate heat. It is also imperative that such fanless power supplies be installed in a case with good ventilation.
- There are also fanless DC to DC power supplies that operate like those in laptops, using an external power brick to supply DC power, which is then converted to appropriate voltages and regulated for use by the computer. These power supplies usually have lower wattage ratings.
The electrical coils in power supplies can produce noise which can become noticeable in a quiet PC.
Cases
Some cases for quiet computers incorporate heatsinks to cool components passively.
Cases that provide lots of space make it easier to quiet a PC, both by allowing for airflow and by accommodating large coolers.
Case airflow
Noise optimized cases like the AntecAntec
Antec, Inc. is an American-based maker of PC components and accessories. Antec's principal products are computer cases and power supplies. Antec also offers PC cooling products and notebook accessories. Founded in 1986, the company is headquartered in Fremont, California, U.S.A., with additional...
P180 and Antec P150 often have ducting and partitioning within the case to optimize airflow and thermally isolate components. For example, the P180 has the PSU mounted in the bottom of the case in an isolated partition. This design feature allows cooler air to enter the PSU, reducing the necessary airflow and accordingly, the noise output of the fan. Apple has also employed this tactic in their G5 workstations in an effort to reduce noise.
Antec's Sonata is often considered by the mainstream to be one of the quietest PC cases; however, it has since been surpassed by the P180 and other more-advanced cases. Vents and ducts may easily be added to regular cases.
More obstructive fan grills increase pressure drop and lower airflow, necessitating higher fan speeds and more noise output. They also increase the turbulence of the flow, which causes some noise of its own. Cases designed to be quiet typically have wire grills or honeycombed fan grills, which perform almost as well as wire grills; both are far superior to the old style of stamped grill.
Features that facilitate neat cable management, such as brackets and space to run cables behind motherboard tray, help increase cooling efficiency.
Air filtering
Air filters can help to prevent dust from coating heatsinks and surfaces, thereby impeding heat transfer, making fans spin faster. However the filter itself can increase noise if it restricts airflow too much, or is not cleaned, requiring a larger or faster fan to handle the pressure drop behind the filter.
Regular cleaning of air intake filters will help to keep airflow minimally restricted and keep the interior clean.
In some cases a fine mesh intake screen is sufficient to stop most large dust particles from entering the system. These screens should be vacuumed or washed to remove dust.
Case soundproofing
The inside of a case can be lined with dampening materialsSoundproofing
Soundproofing is any means of reducing the sound pressure with respect to a specified sound source and receptor. There are several basic approaches to reducing sound: increasing the distance between source and receiver, using noise barriers to reflect or absorb the energy of the sound waves, using...
to reduce noise by:
- attenuating the vibration of the case panels via extensional damping or constrained-layer damping.
- reducing the amplitude of the vibration of the case panels by increasing their mass.
- absorbing airborne noise, such as with foam.
Heat sinks
Heat sinks that operate efficiently with little airflow are often used in quiet computers. Typically they are (relatively) large, and have larger spaces to allow freer airflow. Often heat pipes are used to help distribute heat. For instance, in 2007, the Scythe Ninja or the ThermalrightThermalright
Thermalright is a Taiwan-based company that manufactures high-quality, high-performance aftermarket heat sinks for desktop computers. Thermalright products are primarily marketed towards gamer and enthusiasts who commonly overclock different parts of their computer, generating large amounts of...
Ultra-120 were frequently used as CPU heat sinks in quiet computers.
Fans
Quiet PCs typically use larger (e.g. 120 mm) low-speed fans. Although 140 mm fans are made by some manufacturers, such as Aerocool and Yate Loon, there are very few cases or heatsinks that can use them. Fan adapters, which allow larger fans to be used in place of smaller ones, and fan brackets, like the Zalman FB123, often help when replacing small fans.
Quiet fan manufacturers include Nexus, EBM-Papst, Yate Loon and Scythe. In situations where the resistance to flow is very low, like in free-air conditions, Noctua fans also perform very well. Extensive comparative surveys have been posted by Silent PC Review and MadShrimps.
Fan control
Fan control
Fan control is the management of the rotational speed of an electric fan. There are many types of electric fans and many types of fan controls. This article principally describes the control of a computer fan, to provide adequate cooling while lowering noise....
lers can be used to slow down fans and to precisely choose fan speed. Fan controllers can produce a fixed fan speed using an inline resistor or diode, or a variable speed using a potentiometer
Potentiometer
A potentiometer , informally, a pot, is a three-terminal resistor with a sliding contact that forms an adjustable voltage divider. If only two terminals are used , it acts as a variable resistor or rheostat. Potentiometers are commonly used to control electrical devices such as volume controls on...
or Pulse Width Modulation (PWM). Resistor-based fan control feeds the fan a lower voltage, while PWM fan control rapidly cycles between feeding the fan full voltage and no voltage. PWM fan control reduces rotational speed, and is the easiest and most efficient option for motherboards which have PWM fan headers. This is because PWM fans in conjunction with the motherboard chipset obtain temperature data from Digital Temperature Sensors on the CPU itself. All PWM fans are four pin, and if plugged into a conventional three pin supply will operate at full speed just like a three pin fan.
Fans can also be plugged into the power supply's 5 volt line instead of the 12 volt line (or between the two for a potential difference of 7 volts, although this cripples the fan's speed sensing) to run them at a reduced speed. Most fans will run at 5 volts once they are spinning, but may not start reliably at less than 7 V. Some simple fan controllers will only vary the fans' supply voltage between 8 V and 12 V to avoid this problem entirely. Some fan controllers start the fan at 12 V, then drop the voltage after a few seconds.
Soft mounting fans (e.g. with rubber or silicone fan isolators) can help reduce transfer of fan vibrations to other components.
Intel has recently developed a piezoelectric fan for use in desktop PCs, which is quieter than motor fans and consumes a fraction of the power.
Watercooling
Watercooling is a method of heat-dissipation by transferring the heat through a conductive material which is in contact with a liquid, most often demineralised water and an additive to prevent bacterial growth and provide cosmetic effects. This heated water travels in a loop which usually contains a reservoir, radiator and pump. Recent advances in 12v DC pump technologies (for the first time specifically geared-for pc development) allow for new pumps to be both extremely powerful and extremely quiet. Loops can be made up of any combination of these items and some aren't required such as the radiator or reservoir if alternatives methods are used. The radiator often uses one or more fans to air cool the radiator fins and dissipate the majority of the heat at this point.The most common loop order is reservoir to pump, radiator then the watercooling block and back to the reservoir. The radiator and fan efficiency has the greatest effect on the noise level and cooling efficiency but watercooling is currently the most effective and potentially quietest methods of cooling above ambient temperatures.
There is an inherent danger in the use of water around electrical equipment and leak testing the loop is always recommended before attaching any parts to the motherboard, after all loop connections have been made. The 12v DC pump can be run using batteries or a power supply making sure no power is going to any other part of the system. Because of these risks and the use of water under pressure watercooling is a greater technical challenge to set up due to the number of components and case modification usually required.
Hard drives
Ball bearing
A ball bearing is a type of rolling-element bearing that uses balls to maintain the separation between the bearing races.The purpose of a ball bearing is to reduce rotational friction and support radial and axial loads. It achieves this by using at least two races to contain the balls and transmit...
motors, but these generated excessive noise when the rotational speed of the drive was increased to 5400 RPM or 7200 RPM. More recent desktop hard drives use fluid bearing
Fluid bearing
Fluid bearings are bearings which support the bearing's loads solely on a thin layer of liquid or gas.They can be broadly classified as fluid dynamic bearings or hydrostatic bearings. Hydrostatic bearings are externally pressurized fluid bearings, where the fluid is usually oil, water or air, and...
motors. The first hard drive widely reputed to be quiet was the Seagate
Seagate Technology
Seagate Technology is one of the world's largest manufacturers of hard disk drives. Incorporated in 1978 as Shugart Technology, Seagate is currently incorporated in Dublin, Ireland and has its principal executive offices in Scotts Valley, California, United States.-1970s:On November 1, 1979...
Barracuda ATA IV.
The smaller 2.5" form-factor hard drives generally vibrate less, are quieter, and use less power than the traditional 3.5" drives. On the other hand, they often have lower performance and less capacity, and cost more per gigabyte
Gigabyte
The gigabyte is a multiple of the unit byte for digital information storage. The prefix giga means 109 in the International System of Units , therefore 1 gigabyte is...
.
To minimize vibrations from a hard drive being transferred to, and amplified by, the case, hard drives can be mounted with soft rubber studs, suspended with elastics or placed on soft foam or Sorbothane
Sorbothane
Sorbothane is the brand name of a synthetic viscoelastic urethane polymer used as a shock absorber and vibration damper. It is manufactured by Sorbothane, Inc., based in Kent, Ohio.Sorbothane was invented and patented in 1982 by Dr. Maurice Hiles...
. Hard disk enclosures can also help reduce drive noise. Care must be taken to ensure that the drive gets adequate cooling. Hard disk temperatures can often be monitored by SMART
Self-Monitoring, Analysis, and Reporting Technology
S.M.A.R.T. is a monitoring system for computer hard disk drives to detect and report on various indicators of reliability, in the hope of anticipating failures....
software.
Solid-state drive
Solid-state drive
Solid-state drive
A solid-state drive , sometimes called a solid-state disk or electronic disk, is a data storage device that uses solid-state memory to store persistent data with the intention of providing access in the same manner of a traditional block i/o hard disk drive...
(SSD) storage offers faster seek times, lower power consumption, no moving parts; making it theoretically more reliable and silent. There is scope for very high capacity drives; however, they are currently extremely expensive per GB and are fairly scarce.
Compact Flash cards
A few people use Compact Flash (CF) cards for storage. Because they use a slightly modified Parallel ATA (PATA) interface, a simple adapter is all that is needed to connect CF cards to function as an PATA or PC Card
PC Card
In computing, PC Card is the form factor of a peripheral interface designed for laptop computers. The PC Card standard was defined and developed by the Personal Computer Memory Card International Association which itself was created by a number of computer industry companies in the United States...
hard disk. CF cards are also small, allowing SFF
Small form factor
A small form factor is a computer form factor designed to minimize the volume of a desktop computer. For comparison purposes, the size of an SFF case is usually measured in litres. SFFs are available in a variety of sizes and shapes, including shoeboxes, cubes, and book-sized PCs...
PCs to be made, produce no noise, use very little power (further reducing heat output in the AC/DC conversion in the PSU), and an insignificant amount of heat. However, they are very expensive per GB
Gigabyte
The gigabyte is a multiple of the unit byte for digital information storage. The prefix giga means 109 in the International System of Units , therefore 1 gigabyte is...
and are only available in small capacities.
There are also issues regarding the maximum number of writes to each sector; often specified as 100,000 write cycles. However, there are industrial grade cards which specify a higher number of erase cycles, and different file systems, or technologies such as Enhanced Write Filter
Enhanced Write Filter
Enhanced Write Filter is a component of Windows XP Embedded which filters writes to another medium instead of being physically written to the volume itself. EWF allows the writes to be discarded or committed to the physical volume later...
can reduce the writes to the card. Also, CF cards will fail gradually, so it will be easy to notice before any significant amount of data are lost, unlike the possible immediate failure of HDDs. Due to their small capacities they are easy to back up entirely, and often have 10 year or even lifetime warranties.
Windows minimization projects such as Winimize (Windows 98, less than 20MB) and Linux
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
projects such as Puppy Linux
Puppy Linux
Puppy Linux is a lightweight Linux distribution that focuses on ease of use. The entire system can be run from RAM, allowing the boot medium to be removed after the operating system has started...
mean that running an OS in small capacity, cheap compact flash card is possible. Because they have many OS components removed, they offer a smaller attack surface
Attack surface
The attack surface of a software environment is the code within a computer system that can be run by unauthenticated users. This includes, but is not limited to: user input fields, protocols, interfaces, and services....
for malware
Malware
Malware, short for malicious software, consists of programming that is designed to disrupt or deny operation, gather information that leads to loss of privacy or exploitation, or gain unauthorized access to system resources, or that otherwise exhibits abusive behavior...
to target.
The sustained transfer rate of current CF cards is a maximum of around 25 MB/s, compared to an average of around 70 MB/s for modern hard drives. However, the speed of flash memory is increasing at a faster rate than that of hard drives, and they have minimal seek times compared to hard drives, which increases the speed of loading many small files, and makes the PC seem more responsive as most operations performed by the OS include small files. Due to the fast seek times CF cards also don't show the effects of file system fragmentation
File system fragmentation
In computing, file system fragmentation, sometimes called file system aging, is the inability of a file system to lay out related data sequentially , an inherent phenomenon in storage-backed file systems that allow in-place modification of their contents. It is a special case of data fragmentation...
like hard drives do.
Newer CF cards support faster transfer protocols like DMA. It is possible to use a Compact Flash card for storing only information that isn't changed very often, such as music, videos and binary executables, while storing the small configuration files and other frequently modified data on a small hard drive or i-RAM.
USB flash drives
Where a motherboard supports booting from USB
Universal Serial Bus
USB is an industry standard developed in the mid-1990s that defines the cables, connectors and protocols used in a bus for connection, communication and power supply between computers and electronic devices....
drives, they can be used in a similar fashion to CF cards to run the OS. With some Linux distributions, it is not much harder than using a CF card. As they both use flash memory
Flash memory
Flash memory is a non-volatile computer storage chip that can be electrically erased and reprogrammed. It was developed from EEPROM and must be erased in fairly large blocks before these can be rewritten with new data...
, they have the same advantages and disadvantages, however speed is limited by the USB bus.
Gigabyte i-RAM
The i-RAM is a solid-state disk which has four DIMM slots to allow regular PC RAM to be used like a disk. It is much faster than a hard disk, does not have the write cycle limitations of flash memory, however it requires power continuously in order to maintain its contents (from standby power or a battery when the system is off), uses more power than many laptop hard drives, has maximum capacity of 4 GiB, and is expensive.
Problems and solutions
All forms of affordable solid-state storage offer relatively small capacity. They can be used as main storage for tasks which do not use large amounts of data or large programs, such as web browsing or word processing. Larger files and programs can be stored on a secondary hard drive which is only accessed when needed. Keeping the OS, often accessed files, and smaller programs on a solid-state drive means that the hard drives can be powered down much of the time. Network-attached storage
Network-attached storage
Network-attached storage is file-level computer data storage connected to a computer network providing data access to heterogeneous clients. NAS not only operates as a file server, but is specialized for this task either by its hardware, software, or configuration of those elements...
, or NAS, is another alternative, allowing loud hard drives to be stored remotely.
Small USB drives or CF cards can be used to make the process of network booting easier also.
Optical drives
Optical drives can be slowed down by software to quiet them, such as NeroNero Burning ROM
Nero Multimedia Suite is a popular software suite for Microsoft Windows by Nero AG . Version 10 of this product was released in April 2010.- Included products :The following applications are included in Nero 11 :Disc authoring...
DriveSpeed, or emulated by virtual drive programs such as Daemon Tools
Daemon Tools
Daemon Tools is a disk image emulator and optical disc authoring program for Microsoft Windows. Daemon Tools was originally a furtherance in the development of another program, Generic SafeDisc emulator, and incorporated all of its features. The program claims to be able to defeat most copy...
to eliminate their noise entirely. Notebook optical drives can be used, which tend to be quieter, however this may be because they tend to run slower (typically 24x CD speed, 8x DVD speed). Some DVD drives have a feature, commonly called Riplock
Riplock
Riplock is a characteristic of newer computer DVD-ROM drives that slows the drive transfer rate when reading DVD-Video data, typically to 2x-4x on drives that otherwise could read at 8x or 16x...
, which reduces drive noise by slowing the drive during video playback. For playback operations only 1x (or real time) speed is required.
Laptops
Laptop computers typically do not have power supply fans or video card fans, and they use smaller hard drives. They also use many lower power components. However, laptop CPU coolers are usually smaller, so may be noisier than their desktop counterparts. Limited space, limited access and proprietary components make silencing laptops more difficult.A few laptops do not use cooling fans, for instance the Dell Latitude X1, Panasonic Toughbook W5 and T5, Fujitsu Lifebook P7120. Also, some netbooks, such as the Dell Mini 9, 10 and 12
Dell Inspiron Mini Series
The Dell Inspiron Mini Series was a line of subnotebook/netbook computers designed by Dell. The series was introduced in September 2008 amidst the growing popularity of low-cost netbook computers introduced by competitors, and now consists of the Inspiron Mini 10; with the numbers representing the...
do not have fans. The Mini 9 used SSD rather than a hard disk. The OLPC XO-1
OLPC XO-1
The XO-1, previously known as the $100 Laptop, Children's Machine, and 2B1, is an inexpensive subnotebook computer intended to be distributed to children in developing countries around the world, to provide them with access to knowledge, and opportunities to "explore, experiment and express...
has no internal moving parts.
Monitors
CRTCathode ray tube
The cathode ray tube is a vacuum tube containing an electron gun and a fluorescent screen used to view images. It has a means to accelerate and deflect the electron beam onto the fluorescent screen to create the images. The image may represent electrical waveforms , pictures , radar targets and...
monitors can produce coil noise, as can the external power supply for an LCD
Liquid crystal display
A liquid crystal display is a flat panel display, electronic visual display, or video display that uses the light modulating properties of liquid crystals . LCs do not emit light directly....
monitor or the voltage converter for the monitor's backlight. LCD monitors tend to produce the least noise (whine) from when at full brightness. Reducing brightness using the video card does not introduce whine, but may reduce color accuracy. An LCD monitor with an external power supply tucked out of the way will produce less noticeable noise than one with the power supply built into the screen housing.
Printers
Dot matrixDot matrix printer
A dot matrix printer or impact matrix printer is a type of computer printer with a print head that runs back and forth, or in an up and down motion, on the page and prints by impact, striking an ink-soaked cloth ribbon against the paper, much like the print mechanism on a typewriter...
and daisy wheel
Daisy wheel printer
Daisy wheel printers use an impact printing technology invented in 1969 by David S. Lee at Diablo Data Systems. It uses interchangeable pre-formed type elements, each with typically 96 glyphs, to generate high-quality output comparable to premium typewriters such as the IBM Selectric, but two to...
printers are often noisy, and soundproofed boxes or cabinets can be used to reduce the noise. Another solution is to locate the printer away from the immediate work area or in another room, especially if it can be controlled through a local area network.
External links
- How To Silence A Computer
- SilentPCReview.com - articles on various aspects of PC acoustics
- What is a "Silent" Computer? at SilentPCReview.com
- What is a "Silent" Computer? Dutch (nl)
- Followed by Reference/Recommended and SPCR in a nutshell
- The Silent PC
- Homebuilding of a PWM Fan controller