Sun4d is a computer architecture

Computer architecture

In computer science and engineering, computer architecture is the practical art of selecting and interconnecting hardware components to create computers that meet functional, performance and cost goals and the formal modelling of those systems....

 introduced by
Sun Microsystems

Sun Microsystems

Sun Microsystems, Inc. was a company that sold :computers, computer components, :computer software, and :information technology services. Sun was founded on February 24, 1982...

 in 1992. It is a development of the earlier Sun-4

Sun-4

Sun-4 is a series of Unix workstations and servers produced by Sun Microsystems, launched in 1987. The original Sun-4 series were VMEbus-based systems similar to the earlier Sun-3 series, but employing microprocessors based on Sun's own SPARC V7 RISC architecture in place of the 68k family...

 architecture, using the XDBus system bus,
SuperSPARC

SPARC

SPARC is a RISC instruction set architecture developed by Sun Microsystems and introduced in mid-1987....

 processors, and SBus

SBus

SBus is a computer bus system that was used in most SPARC-based computers from Sun Microsystems and others during the 1990s...

 I/O

I/O

I/O may refer to:* Input/output, a system of communication for information processing systems* Input-output model, an economic model of flow prediction between sectors...

 cards. The XDBus
was the result of a collaboration between Sun
and Xerox

Xerox

Xerox Corporation is an American multinational document management corporation that produced and sells a range of color and black-and-white printers, multifunction systems, photo copiers, digital production printing presses, and related consulting services and supplies...

; its name comes from an earlier Xerox
project, the Xerox Dragon. These were Sun's largest machines to date, and
their first attempt at making a mainframe

Mainframe computer

Mainframes are powerful computers used primarily by corporate and governmental organizations for critical applications, bulk data processing such as census, industry and consumer statistics, enterprise resource planning, and financial transaction processing.The term originally referred to the...

-class server.

Architecture

Sun4d computers are true SMP

Symmetric multiprocessing

In computing, symmetric multiprocessing involves a multiprocessor computer hardware architecture where two or more identical processors are connected to a single shared main memory and are controlled by a single OS instance. Most common multiprocessor systems today use an SMP architecture...

 systems;
although memory and CPUs are installed per system board, the memory on
a given board is not in any way "closer" to the CPUs on that same
board. All memory and I/O devices are equally connected to all CPUs.

All of these computers use a passive backplane into which system
boards are plugged. Each system board provides CPUs, memory, and
an I/O bus. As system boards are added, these components are
added to the whole in a completely seamless fashion. It is not
a cluster, but works as a single large machine.

Machines

Sun4d computers include the SPARCcenter 2000 (1992) and
SPARCserver 1000 (1993) from Sun Microsystems, and the
Cray CS6400

Cray CS6400

The Cray Superserver 6400, or CS6400, was a multiprocessor server computer system produced by Cray Research Superservers, Inc., a subsidiary of Cray Research, and launched in 1993...

 (1993) from Cray Research

Cray

Cray Inc. is an American supercomputer manufacturer based in Seattle, Washington. The company's predecessor, Cray Research, Inc. , was founded in 1972 by computer designer Seymour Cray. Seymour Cray went on to form the spin-off Cray Computer Corporation , in 1989, which went bankrupt in 1995,...

.
The system boards in these three machines are all slightly
different, physically and electronically, and are
not interchangeable.

All Sun4d machines provide JTAG

JTAG

Joint Test Action Group is the common name for what was later standardized as the IEEE 1149.1 Standard Test Access Port and Boundary-Scan Architecture. It was initially devised for testing printed circuit boards using boundary scan and is still widely used for this application.Today JTAG is also...

 ports, although unlike later systems the SPARCcenter and SPARCserver only use it for maintenance purposes.

SPARCserver 1000

The SPARCserver 1000 is a 5U

Rack unit

A rack unit or U is a unit of measure used to describe the height of equipment intended for mounting in a 19-inch rack or a 23-inch rack...

 rackmountable chassis with four 40 MHz XDBus slots,
and space for four half-height 3.5" SCSI

SCSI

Small Computer System Interface is a set of standards for physically connecting and transferring data between computers and peripheral devices. The SCSI standards define commands, protocols, and electrical and optical interfaces. SCSI is most commonly used for hard disks and tape drives, but it...

 drives plus two half-height
front-accessible 5.25" SCSI drives (typically used for CD-ROM

CD-ROM

A CD-ROM is a pre-pressed compact disc that contains data accessible to, but not writable by, a computer for data storage and music playback. The 1985 “Yellow Book” standard developed by Sony and Philips adapted the format to hold any form of binary data....

 and DAT

Digital Data Storage

Digital Data Storage is a format for storing computer data on a Digital Audio Tape .DDS uses tape with a width of 3.8mm, with the exception of the latest formats, DAT 160 and DAT 320, which are 8mm wide...

). Each
system board connects to one XDBus and provides two MBus slots
for CPUs, three SBus slots for I/O boards, four banks of memory
(four SIMMs apiece), and builtin SCSI-2, 10baseT Ethernet

Ethernet

Ethernet is a family of computer networking technologies for local area networks commercially introduced in 1980. Standardized in IEEE 802.3, Ethernet has largely replaced competing wired LAN technologies....

, and two serial ports.

Maximum configuration: eight CPUs and 2 GB RAM.

The SPARCserver 1000E has a slightly faster XDBus (50 MHz). The system boards are not backwards compatible.

The SPARCserver 1000, like earlier Sun-4

Sun-4

Sun-4 is a series of Unix workstations and servers produced by Sun Microsystems, launched in 1987. The original Sun-4 series were VMEbus-based systems similar to the earlier Sun-3 series, but employing microprocessors based on Sun's own SPARC V7 RISC architecture in place of the 68k family...

/xxx servers, has a set of LEDs on each system board that display diagnostics on POST

Power-on self-test

Power-On Self-Test refers to routines run immediately after power is applied, by nearly all electronic devices. Perhaps the most widely-known usage pertains to computing devices...

, and CPU load while running. These allow the user to see at a glance how busy each processor on the system is. They are informally referred to as "Cylon" displays, because of the way each displays a single light bouncing back and forth resembles the scanner of the robots

Cylon (1978)

Cylons are a fictional race of robots in the original Battlestar Galactica TV series. They are the primary antagonists of the series and are at war with the Twelve Colonies of humanity. The Cylons also appeared in the short-lived 1980 spin-off series Galactica 1980.The Cylons were created by a...

 in the original Battlestar Galactica

Battlestar Galactica

Battlestar Galactica is an American science fiction franchise created by Glen A. Larson. The franchise began with the Battlestar Galactica TV series in 1978, and was followed by a brief sequel TV series in 1980, a line of book adaptations, original novels, comic books, a board game, and video games...

television series.

The SPARCserver 1000 will run a slightly-patched 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...

 2.4 kernel in SMP mode.

SPARCcenter 2000

The SPARCcenter 2000 is a full rack system that includes a main chassis with ten 40MHz dual-XDBus slots and several disk arrays. The system boards connect to two XDBuses for extra bandwidth, and provide two MBus slots, four SBus slots, four banks of memory (four SIMM

SIMM

A SIMM, or single in-line memory module, is a type of memory module containing random access memory used in computers from the early 1980s to the late 1990s. It differs from a dual in-line memory module , the most predominant form of memory module today, in that the contacts on a SIMM are redundant...

s apiece), and two serial ports apiece. Unlike the SPARCserver 1000 boards, they do not have a builtin SCSI and Ethernet port per system board.

Maximum configuration: twenty CPUs and 5 GB RAM.

The SPARCcenter 2000E has a slightly faster XDBus (50 MHz). The system boards are not backwards compatible.

Cray Superserver 6400

The Cray CS6400

Cray CS6400

The Cray Superserver 6400, or CS6400, was a multiprocessor server computer system produced by Cray Research Superservers, Inc., a subsidiary of Cray Research, and launched in 1993...

 is a 16-slot, 55 MHz quad-XDBus system. Each system board provides four MBus slots, four SBus slots, four banks of memory, and no builtin I/O ports.

Maximum configuration: sixty-four CPUs and 16 GB RAM.

When SGI

Silicon Graphics

Silicon Graphics, Inc. was a manufacturer of high-performance computing solutions, including computer hardware and software, founded in 1981 by Jim Clark...

 purchased Cray Research in 1996, they sold the division responsible for the CS6400 to Sun, where it was developed into the extremely successful Sun Enterprise 10000.

Performance

Relative performance of Sun-4d machines, based on SPEC

Standard Performance Evaluation Corporation

The Standard Performance Evaluation Corporation is a non-profit organization that aims to "produce, establish, maintain and endorse a standardized set" of performance benchmarks for computers....

CINT92 Rate benchmarks:

System	Processors	geometric mean rate_int92	008 espresso SPEC rate	022 li SPEC rate	023 eqntott SPEC rate	026 compress SPEC rate	072 sc SPEC rate	085 gcc SPEC rate
CS6400	64	101969	98449	147287	139144	32849	214882	78932
SC2000E	20	53714	46817	54551	74541	28564	107441	41111
SS1000E	8	21758	19578	26184	26089	11680	45238	15014