Sequent Computer Systems, Inc. was a computer company that designed and manufactured

multiprocessing Multiprocessing (MP) is the use of two or more central processing units (CPUs) within a single computer system. The term also refers to the ability of a system to support more than one processor or the ability to allocate tasks between them. The ...

computer system A computer is a machine that can be programmed to automatically carry out sequences of arithmetic or logical operations (''computation''). Modern digital electronic computers can perform generic sets of operations known as ''programs'', wh ...

s. They were among the pioneers in high-performance

symmetric multiprocessing Symmetric multiprocessing or shared-memory multiprocessing (SMP) involves a multiprocessor computer hardware and software architecture where two or more identical processors are connected to a single, shared main memory, have full access to all ...

(SMP) open systems, innovating in both hardware (e.g.,

cache Cache, caching, or caché may refer to: Science and technology * Cache (computing), a technique used in computer storage for easier data access * Cache (biology) or hoarding, a food storing behavior of animals * Cache (archaeology), artifacts p ...

management and

interrupt In digital computers, an interrupt (sometimes referred to as a trap) is a request for the processor to ''interrupt'' currently executing code (when permitted), so that the event can be processed in a timely manner. If the request is accepted ...

handling) and software (e.g.,

read-copy-update In computer science, read-copy-update (RCU) is a synchronization mechanism that avoids the use of lock primitives while multiple threads concurrently read and update elements that are linked through pointers and that belong to shared data structur ...

). Through a partnership with

Oracle Corporation Oracle Corporation is an American Multinational corporation, multinational computer technology company headquartered in Austin, Texas. Co-founded in 1977 in Santa Clara, California, by Larry Ellison, who remains executive chairman, Oracle was ...

, Sequent became a dominant high-end

UNIX Unix (, ; trademarked as UNIX) is a family of multitasking, multi-user computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, a ...

platform in the late 1980s and early 1990s. Later they introduced a next-generation high-end platform for UNIX and

Windows NT Windows NT is a Proprietary software, proprietary Graphical user interface, graphical operating system produced by Microsoft as part of its Windows product line, the first version of which, Windows NT 3.1, was released on July 27, 1993. Original ...

based on a

non-uniform memory access Non-uniform memory access (NUMA) is a computer storage, computer memory design used in multiprocessing, where the memory access time depends on the memory location relative to the processor. Under NUMA, a processor can access its own local memory ...

architecture, NUMA-Q. As hardware prices fell in the late 1990s, and

Intel Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California, and Delaware General Corporation Law, incorporated in Delaware. Intel designs, manufactures, and sells computer compo ...

shifted their server focus to the

Itanium Itanium (; ) is a discontinued family of 64-bit computing, 64-bit Intel microprocessors that implement the Intel Itanium architecture (formerly called IA-64). The Itanium architecture originated at Hewlett-Packard (HP), and was later jointly dev ...

processor family, Sequent joined the

Project Monterey Project Monterey was an attempt to build a single Unix operating system that ran across a variety of 32-bit and 64-bit platforms, as well as supporting multi-processing. It would allow applications to run across a wide selection of machines, at ...

effort in October 1998, which aimed to move a standard Unix to several new platforms.Sequent was overmatched, CEO says
a July 1999 article from CNET Networks In July 1999 Sequent agreed to be acquired by IBM.Sequent Computer Systems To Be Acquired by I.B.M.
a July 13, 1999 article from ''

The New York Times ''The New York Times'' (''NYT'') is an American daily newspaper based in New York City. ''The New York Times'' covers domestic, national, and international news, and publishes opinion pieces, investigative reports, and reviews. As one of ...

'' At the time, Sequent's CEO said its technology would "find its way through IBM's entire product field" and IBM announced it would "both sell Sequent machines, and fold Sequent's technology...into its own servers", but by May 2002 a decline in sales of the models acquired from Sequent, among other reasons, led to the retirement of Sequent-heritage products. Vestiges of Sequent's innovations live on in the form of data clustering software from PolyServe (subsequently acquired by HP), various projects within

OSDL Open Source Development Labs (OSDL) was a non-profit organization supported by a consortium to promote Linux for enterprise computing. Founded in 2000, OSDL positioned itself as an independent, non-profit lab for developers who are adding enterpris ...

, IBM contributions to the

Linux kernel The Linux kernel is a Free and open-source software, free and open source Unix-like kernel (operating system), kernel that is used in many computer systems worldwide. The kernel was created by Linus Torvalds in 1991 and was soon adopted as the k ...

, and claims in the '' SCO v. IBM'' lawsuit.

History

Originally named Sequel, Sequent was formed in 1983 when a group of seventeen engineers and executives left

after the failed

iAPX 432 The iAPX 432 (''Intel Advanced Performance Architecture'') is a discontinued computer architecture introduced in 1981. It was Intel's first 32-bit processor design. The main processor of the architecture, the ''general data processor'', is im ...

"mainframe on a chip" project was cancelled; they were joined by one non-

employee. They started Sequent to develop a line of SMP computers, then considered one of the up-and-coming fields in computer design.

Balance

Sequent's first computer systems were the Balance 8000 (released in 1984) and Balance 21000 (released in 1986). Both models were based on 10 MHz

National Semiconductor National Semiconductor Corporation was an United States of America, American Semiconductor manufacturing, semiconductor manufacturer, which specialized in analogue electronics, analog devices and subsystems, formerly headquartered in Santa Clara, ...

NS32032 The NS32000, sometimes known as the 32k, is a series of microprocessors produced by National Semiconductor. Design work began around 1980 and it was announced at the International Solid-State Circuits Conference in April 1981. The first member o ...

processors, each with a small write-through cache connected to a common memory to form a shared memory system. The Balance 8000 supported up to 6 dual-processor boards for a total maximum of 12 processors.Machines. Sequent
cs.berkeley.edu The Balance 21000 supported up to 15 dual-processor boards for a total maximum of 30 processors. The systems ran a modified version of

4.2BSD The history of the Berkeley Software Distribution began in the 1970s when University of California, Berkeley received a copy of Unix. Professors and students at the university began adding software to the operating system and released it as BSD to ...

Unix Unix (, ; trademarked as UNIX) is a family of multitasking, multi-user computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, a ...

the company called

DYNIX DYNIX (''DYNamic UnIX'') was a Unix-like operating system developed by Sequent Computer Systems, based on 4.2BSD and modified to run on Intel-based symmetric multiprocessor hardware. The third major (Dynix 3.0) version was released May, 1987; b ...

, for DYNamic unIX. The machines were designed to compete with the DEC

VAX-11/780 The VAX-11 is a discontinued family of 32-bit superminicomputers, running the Virtual Address eXtension (VAX) instruction set architecture (ISA), developed and manufactured by Digital Equipment Corporation (DEC). Development began in 1976. In ad ...

, with all of their inexpensive processors available to run any process. In addition the system included a series of libraries that could be used by programmers to develop applications that could use more than one processor at a time.

Symmetry

Their next series was the

Intel 80386 The Intel 386, originally released as the 80386 and later renamed i386, is the third-generation x86 architecture microprocessor from Intel. It was the first 32-bit computing, 32-bit processor in the line, making it a significant evolution in ...

-based Symmetry, released in 1987. Various models supported between 2 and 30 processors, using a new copy-back cache and a wider

64-bit In computer architecture, 64-bit integers, memory addresses, or other data units are those that are 64 bits wide. Also, 64-bit central processing units (CPU) and arithmetic logic units (ALU) are those that are based on processor registers, a ...

memory bus In computer architecture, a bus (historically also called a data highway or databus) is a communication system that transfers data between components inside a computer or between computers. It encompasses both hardware (e.g., wires, optica ...

. 1991's Symmetry 2000 models added multiple

SCSI Small Computer System Interface (SCSI, ) is a set of standards for physically connecting and transferring data between computers and peripheral devices, best known for its use with storage devices such as hard disk drives. SCSI was introduced ...

boards, and were offered in versions with from one to six

Intel 80486 The Intel 486, officially named i486 and also known as 80486, is a microprocessor introduced in 1989. It is a higher-performance follow-up to the i386, Intel 386. It represents the fourth generation of binary compatible CPUs following the Inte ...

processors. The next year they added the

VMEbus VMEbus (Versa Module Eurocard bus) is a computer bus standard physically based on Eurocard sizes. History In 1979, during development of the Motorola 68000 CPU, one of their engineers, Jack Kister, decided to set about creating a standar ...

based Symmetry 2000/x50 with faster CPUs. Sequent S81

The late 1980s and early 1990s saw big changes on the software side for Sequent. DYNIX was replaced by DYNIX/ptx, which was based on a merger of

AT&T Corporation AT&T Corporation, an abbreviation for its former name, the American Telephone and Telegraph Company, was an American telecommunications company that provided voice, video, data, and Internet telecommunications and professional services to busi ...

UNIX System V Unix System V (pronounced: "System Five") is one of the first commercial versions of the Unix operating system. It was originally developed by AT&T and first released in 1983. Four major versions of System V were released, numbered 1, 2, 3, an ...

and

. And this was during a period when Sequent's high-end systems became particularly successful due to a close working relationship with

Oracle An oracle is a person or thing considered to provide insight, wise counsel or prophetic predictions, most notably including precognition of the future, inspired by deities. If done through occultic means, it is a form of divination. Descript ...

, specifically their high-end database servers. In 1993 they added the Symmetry 2000/x90 along with their ptx/Cluster software, which added various

high availability High availability (HA) is a characteristic of a system that aims to ensure an agreed level of operational performance, usually uptime, for a higher than normal period. There is now more dependence on these systems as a result of modernization ...

features and introduced custom support for Oracle Parallel Server. In 1994 Sequent introduced the Symmetry 5000 series models SE20, SE60 and SE90, which used 66 MHz

Pentium Pentium is a series of x86 architecture-compatible microprocessors produced by Intel from 1993 to 2023. The Pentium (original), original Pentium was Intel's fifth generation processor, succeeding the i486; Pentium was Intel's flagship proce ...

CPUs in systems from 2 to 30 processors. The next year they expanded that with the SE30/70/100 lineup using 100 MHz Pentiums, and then in 1996 with the SE40/80/120 with 166 MHz Pentiums. A variant of the Symmetry 5000, the WinServer 5000 series, ran

instead of DYNIX/ptx.

NUMA

Recognizing the increase in competition for SMP systems after having been early adopters of the architecture, and the increasing integration of SMP technology into microprocessors, Sequent sought its next source of differentiation. They began investing in the development of a system based on a cache-coherent non-uniform memory architecture (

ccNUMA Non-uniform memory access (NUMA) is a computer memory design used in multiprocessing, where the memory access time depends on the memory location relative to the processor. Under NUMA, a processor can access its own local memory faster than non- ...

) and leveraging

Scalable Coherent Interconnect The Scalable Coherent Interface or Scalable Coherent Interconnect (SCI), is a high-speed interconnect standard for shared memory multiprocessing and message passing. The goal was to scale well, provide system-wide memory coherence and a simple in ...

. NUMA distributes memory among the processors, avoiding the

bottleneck Bottleneck may refer to: * the narrowed portion (neck) of a bottle Science and technology * Bottleneck (engineering), where the performance of an entire system is limited by a single component * Bottleneck (network), in a communication network * ...

that occurs with a single monolithic memory. Using NUMA would allow their multiprocessor machines to generally outperform SMP systems, at least when the tasks can be executed close to their memory — as is the case for

server Server may refer to: Computing *Server (computing), a computer program or a device that provides requested information for other programs or devices, called clients. Role * Waiting staff, those who work at a restaurant or a bar attending custome ...

s, where tasks typically do not share large amounts of data. In 1996 they released the first of a new series of machines based on this new architecture. Known internally as STiNG, an

abbreviation An abbreviation () is a shortened form of a word or phrase, by any method including shortening (linguistics), shortening, contraction (grammar), contraction, initialism (which includes acronym), or crasis. An abbreviation may be a shortened for ...

for ''Sequent: The Next Generation (with Intel inside)'', it was productized as NUMA-Q and was the last of the systems released before the company was purchased by IBM for over $800 million. IBM then started

with

Santa Cruz Operation The Santa Cruz Operation, Inc. (usually known as SCO, pronounced either as individual letters or as a word) was an American software company, based in Santa Cruz, California, that was best known for selling three Unix operating system variants ...

, intending to produce a NUMA-capable standardized

running on

IA-32 IA-32 (short for "Intel Architecture, 32-bit", commonly called ''i386'') is the 32-bit version of the x86 instruction set architecture, designed by Intel and first implemented in the i386, 80386 microprocessor in 1985. IA-32 is the first incarn ...

IA-64 IA-64 (Intel Itanium architecture) is the instruction set architecture (ISA) of the discontinued Itanium family of 64-bit Intel microprocessors. The basic ISA specification originated at Hewlett-Packard (HP), and was subsequently implemented by ...

and

POWER Power may refer to: Common meanings * Power (physics), meaning "rate of doing work" ** Engine power, the power put out by an engine ** Electric power, a type of energy * Power (social and political), the ability to influence people or events Math ...

and

PowerPC PowerPC (with the backronym Performance Optimization With Enhanced RISC – Performance Computing, sometimes abbreviated as PPC) is a reduced instruction set computer (RISC) instruction set architecture (ISA) created by the 1991 Apple Inc., App ...

platforms. This project later fell through as both IBM and SCO turned to the

Linux Linux ( ) is a family of open source Unix-like operating systems based on the Linux kernel, an kernel (operating system), operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically package manager, pac ...

market, but is the basis for "the new SCO"'s '' SCO v. IBM'' Linux lawsuit.

IBM purchase and disappearance

With their future product strategy in tatters, it appeared Sequent had little future standing alone, and was purchased by IBM in 1999 for $810 million. IBM released several x86 servers with a NUMA architecture. The first was the x440 in August, 2002 with a follow-on x445 in 2003. In 2004, an Itanium-based x455 was added to the NUMA family. During this period, NUMA technology became the basis for IBM's extended X-Architecture (eXA, which could also stand for enterprise X-Architecture). As of 2011, this chipset is now on its fifth generation, known as eX5 technology. It now falls under the brand

IBM System x System x is a line of x86 servers produced by IBM, and later by Lenovo, as a sub-brand of IBM's ''System'' brand, alongside IBM Power Systems, IBM System z and IBM System Storage. In addition, IBM System x was the main component of the IBM Syst ...

. According to a May 30, 2002 article in the ''

Wall Street Journal ''The Wall Street Journal'' (''WSJ''), also referred to simply as the ''Journal,'' is an American newspaper based in New York City. The newspaper provides extensive coverage of news, especially business and finance. It operates on a subscriptio ...

'' (WSJ) entitled "Sequent Deal Serves Hard Lesson for IBM": :When IBM bought Sequent, ...it equentlacked the size and resources to compete with

Sun The Sun is the star at the centre of the Solar System. It is a massive, nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy from its surface mainly as visible light a ...

and Hewlett-Packard Co. in the Unix server market.... :In 1999, IBM had problems of its own with an aged and high-priced line of

s, particularly for its version of Unix known as

AIX Aix or AIX may refer to: Computing * AIX, a line of IBM computer operating systems *Alternate index, for an IBM Virtual Storage Access Method key-sequenced data set * Athens Internet Exchange, a European Internet exchange point Places Belg ...

. It also faced huge losses in

personal computer A personal computer, commonly referred to as PC or computer, is a computer designed for individual use. It is typically used for tasks such as Word processor, word processing, web browser, internet browsing, email, multimedia playback, and PC ...

s and declining sales in its cash-cow mainframe line.

Detailed model descriptions

The following is a more detailed description of the first two generations of Symmetry products, released between 1987 and 1990.

Symmetry S-series

;Symmetry S3: The S3 was the low-end platform based on commodity PC components running a fully compatible version of DYNIX 3. It featured a single 33

MHz The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), often described as being equivalent to one event (or cycle) per second. The hertz is an SI derived unit whose formal expression in terms of SI base u ...

processor, up to 40

megabyte The megabyte is a multiple of the unit byte for digital information. Its recommended unit symbol is MB. The unit prefix ''mega'' is a multiplier of (106) in the International System of Units (SI). Therefore, one megabyte is one million bytes ...

s of RAM, up to 1.8

gigabyte The gigabyte () is a multiple of the unit byte for digital information. The SI prefix, prefix ''giga-, giga'' means 109 in the International System of Units (SI). Therefore, one gigabyte is one billion bytes. The unit symbol for the gigabyte i ...

s of

-based disk storage, and up to 32 direct-connected

serial port A serial port is a serial communication Interface (computing), interface through which information transfers in or out sequentially one bit at a time. This is in contrast to a parallel port, which communicates multiple bits simultaneously in Pa ...

s. ;Symmetry S16: The S16 was the entry-level multiprocessing model, which ran DYNIX/ptx. It featured up to six 20 MHz Intel 80386 processors, each with a 128

kilobyte The kilobyte is a multiple of the unit byte for Computer data storage, digital information. The International System of Units (SI) defines the prefix ''kilo-, kilo'' as a multiplication factor of 1000 (103); therefore, one kilobyte is 1000&nbs ...

. It also supported up to 80 MB of RAM, up to 2.5 GB of SCSI-based disk storage, and up to 80 direct-connected serial ports. ;Symmetry S27: The S27 ran either DYNIX/ptx or DYNIX 3. It featured up to ten 20 MHz Intel 80386 processors, each with a 128 KB cache. It also supported up to 128 MB of RAM, up to 12.5 GB of disk storage, and up to 144 direct-connected serial ports. ;Symmetry S81: The S81 ran either DYNIX/ptx or DYNIX 3. It featured up to 30 20 MHz Intel 80386 processors, each with a 128 KB cache. It also supported up to 384 MB of RAM, up to 84.8 GB of disk storage, and up to 256 direct-connected serial ports.

Symmetry 2000 series

;Symmetry 2000/40: The S2000/40 was the low-end platform based on commodity PC components running a fully compatible version of DYNIX/ptx. It featured a single 33

processor, up to 64

s of RAM, up to 2.4

s of

-based disk storage, and up to 32 direct-connected

s. ;Symmetry 2000/200: The S2000/200 was the entry-level multiprocessing model, which ran DYNIX/ptx. It featured up to six 25 MHz Intel 80486 processors, each with a 512

. It also supported up to 128 MB of RAM, up to 2.5 GB of SCSI-based disk storage, and up to 80 direct-connected serial ports. ;Symmetry 2000/400: The S2000/400 ran either DYNIX/ptx or DYNIX 3. It featured up to ten 25 MHz Intel 80486 processors, each with a 512 KB cache. It also supported up to 128 MB of RAM, up to 14.0 GB of disk storage, and up to 144 direct-connected serial ports. ;Symmetry 2000/700: The S2000/700 ran either DYNIX/ptx or DYNIX 3. It featured up to 30 25 MHz Intel 80486 processors, each with a 512 KB cache. It also supported up to 384 MB of RAM, up to 85.4 GB of disk storage, and up to 256 direct-connected serial ports.

References

External links

* {{Authority control 1983 establishments in Oregon 1999 disestablishments in Oregon 1999 mergers and acquisitions American companies established in 1983 American companies disestablished in 1999 Beaverton, Oregon Computer companies established in 1983 Computer companies disestablished in 1999 Defunct companies based in Oregon Defunct computer companies of the United States Defunct computer hardware companies Defunct computer systems companies IBM acquisitions

History

Balance

Symmetry

NUMA

IBM purchase and disappearance

Detailed model descriptions

Symmetry S-series

Symmetry 2000 series

See also

References

External links