Alliant Computer Systems
Encyclopedia
Alliant Computer Systems was a computer company that designed and manufactured parallel computing
systems. Together with Pyramid Technology
and Sequent Computer Systems
, Alliant's machines pioneered the symmetric multiprocessing
market. One of the more successful companies in the group, over 650 Alliant systems were produced over their lifetime.
and Rich McAndrew to produce machines for scientific and engineering users who needed smaller, less costly machines than offerings from Cray Computer and similar high-end vendors. Machines that addressed this market segment later became known as minisupercomputers
.
Alliant's first machines were announced in 1985, starting with the FX series. The FX series consisted of a number Computational Elements, or CEs, which included a set of Weitek
1064/1065 FPU
's and several custom designed support chips to implement a vector processor
based upon the popular Motorola 68000 architecture. These were augmented by the Interactive Processors, IPs, which used Motorola 68008
's (and, subsequently, Motorola 68010
's and then Motorola 68020
's) with 4MB of local RAM, connecting everything together using a crossbar switch to a globally shared cache. The shared cache and a special concurrency bus implemented low latency concurrency control that could be exploited automatically by high level language compilers to provide data-parallel
processing among the CEs. Like many early multiprocessing
systems, the FX series ran a stripped down version of 4.2 BSD Unix on the IPs and CEs, known as Concentrix. In time more 4.2 BSD features were added.
Systems were numerated for the largest potential number of CEs inside, the FX/1, FX/4 and FX/8. Alliant machines were fairly small, the FX/1 was about the size of a large full-height PC, while the FX/8 was smaller than a VAX-11/780
, about the size of a large photocopier
. The speed of an FX/1 was about 2.5 MIPS (million instructions per second) and compared favorably to the 1 MIPS VAX-11/780. A fully populated eight CE FX/8, with eight times the aggregate MIPS, was in practice around five times faster than the FX/1 at solving problems that allowed a high degree of parallel computation (see Amdahl's law).
A second series of FX machines, introduced in early 1988, replaced the CE with new custom hardware known as the Advanced Computational Element (ACE). The Weitek FPUs were replaced by a floating point chipset made by Bipolar Integrated Technology
and a redesigned vector processor
with 32 64-bit vector elements, 8 64-bit scalar floating point registers, 8 32-bit integer registers, and 8 32-bit address registers. The new vector processor increased vector processing speed while reducing board space allowing the ACE to return to the 18x18 inch profile used by the other system boards in the main chassis. These were used in the FX/40, FX/80 and VFX machines.
RISC chip. The i860 was an early superscalar
CPU that allowed the programmer access directly into the pipelines; with custom coding the 860 was a very fast system, making it perfect for supercomputer
applications. In the new series the Super Computational Element (SCE) and Super Interactive Processor (SIP) both consisted of up to four i860s, up to seven of which could be interconnected on the crossbar. A fully expanded FX/2800 could support 28 i860's in total.
Also in 1990 Alliant purchased Raster Technologies, a provider of high-resolution graphics
terminals and custom graphics cards for Sun Microsystems
workstations. Their GX4000 product was a combination of PHIGS+
software and special graphical boards that could generate and display graphical vectors very fast. For 3D effects, a hardware Z-buffer was available. The Raster graphics technology was integrated with FX/40 and FX/80 machines to produce the VFX, Alliant's first fully integrated graphical minisupercomputer
.
Alliant's final product series was the CAMPUS/800, a massively parallel machine based on units similar to the FX/2800 known as ClusterNodes and sharing a total of up to 4GB of unified memory. Each ClusterNode was connected to up to 32 others with an intra-ClusterNode switch, with a latency of 1us and 1.12GB/s bandwidth. An inter-ClusterNode switch based on HIPPI
was also available, with a latency of 30us and 2.56GB/s bandwidth. The largest CAMPUS system created included 192 ClusterNodes in total, and provided 4.7 GFLOPS.
The CAMPUS/800 was first announced in 1991, but the company was hit by a series financial problems and went bankrupt in 1992. Various Alliant systems soldiered on in service for many years after that however, and were generally considered very reliable.
The Computer History Museum
has examples of the FX/8 and FX/1 (from Convex Computer Corporation after Alliant's fall), but is seeking examples of FX/80 and FX/2800 configurations.
Parallel computing
Parallel computing is a form of computation in which many calculations are carried out simultaneously, operating on the principle that large problems can often be divided into smaller ones, which are then solved concurrently . There are several different forms of parallel computing: bit-level,...
systems. Together with Pyramid Technology
Pyramid Technology
Pyramid Technology Corporation was a computer company that produced a number of RISC-based minicomputers at the upper end of the performance range. They also became the second company to ship a multiprocessor Unix system , in 1985, which formed the basis of their product line into the early 1990s...
and Sequent Computer Systems
Sequent Computer Systems
Sequent Computer Systems, or Sequent, was a computer company that designed and manufactured multiprocessing computer systems. They were among the pioneers in high-performance symmetric multiprocessing open systems, innovating in both hardware and software Sequent Computer Systems, or Sequent, was...
, Alliant's machines pioneered the symmetric multiprocessing
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...
market. One of the more successful companies in the group, over 650 Alliant systems were produced over their lifetime.
1980s
Alliant was founded, as Dataflow Systems, in May 1982 by Ron Gruner, Craig MundieCraig Mundie
Craig James Mundie is chief research and strategy officer at Microsoft. He started in its consumer platforms division in 1992, managing the production of Windows CE for hand-held and automotive systems and early console games. In 1997, Mundie oversaw the acquisition of WebTV Networks...
and Rich McAndrew to produce machines for scientific and engineering users who needed smaller, less costly machines than offerings from Cray Computer and similar high-end vendors. Machines that addressed this market segment later became known as minisupercomputers
Minisupercomputer
Minisupercomputers constituted a short-lived class of computers that emerged in the mid-1980s. As scientific computing using vector processors became more popular, the need for lower-cost systems that might be used at the departmental level instead of the corporate level created an opportunity for...
.
Alliant's first machines were announced in 1985, starting with the FX series. The FX series consisted of a number Computational Elements, or CEs, which included a set of Weitek
Weitek
Weitek Corporation was a chip-design company that originally concentrated on floating point units for a number of commercial CPU designs. During the early to mid-1980s, Weitek designs could be found powering a number of high-end designs and parallel processing supercomputers...
1064/1065 FPU
Floating point unit
A floating-point unit is a part of a computer system specially designed to carry out operations on floating point numbers. Typical operations are addition, subtraction, multiplication, division, and square root...
's and several custom designed support chips to implement a vector processor
Vector processor
A vector processor, or array processor, is a central processing unit that implements an instruction set containing instructions that operate on one-dimensional arrays of data called vectors. This is in contrast to a scalar processor, whose instructions operate on single data items...
based upon the popular Motorola 68000 architecture. These were augmented by the Interactive Processors, IPs, which used Motorola 68008
Motorola 68008
The Motorola 68008 is an 8/16/32-bit microprocessor made by Motorola. It is a version of the Motorola 68000 with an 8-bit external data bus, as well as a smaller address bus.The original 68000 had a 24-bit address bus and a 16-bit data bus...
's (and, subsequently, Motorola 68010
Motorola 68010
The Motorola MC68010 processor is a 16/32-bit microprocessor from Motorola, released in 1982. In line with the Motorola 68000 naming convention, it is usually just referred to as the 010 ....
's and then Motorola 68020
Motorola 68020
The Motorola 68020 is a 32-bit microprocessor from Motorola, released in 1984. It is the successor to the Motorola 68010 and is succeeded by the Motorola 68030...
's) with 4MB of local RAM, connecting everything together using a crossbar switch to a globally shared cache. The shared cache and a special concurrency bus implemented low latency concurrency control that could be exploited automatically by high level language compilers to provide data-parallel
Data parallelism
Data parallelism is a form of parallelization of computing across multiple processors in parallel computing environments. Data parallelism focuses on distributing the data across different parallel computing nodes...
processing among the CEs. Like many early multiprocessing
Multiprocessing
Multiprocessing is the use of two or more central processing units within a single computer system. The term also refers to the ability of a system to support more than one processor and/or the ability to allocate tasks between them...
systems, the FX series ran a stripped down version of 4.2 BSD Unix on the IPs and CEs, known as Concentrix. In time more 4.2 BSD features were added.
Systems were numerated for the largest potential number of CEs inside, the FX/1, FX/4 and FX/8. Alliant machines were fairly small, the FX/1 was about the size of a large full-height PC, while the FX/8 was smaller than a VAX-11/780
VAX-11
The VAX-11 was a family of minicomputers developed and manufactured by Digital Equipment Corporation using processors implementing the VAX instruction set architecture . The VAX-11/780 was the first VAX computer.- VAX-11/780 :...
, about the size of a large photocopier
Photocopier
A photocopier is a machine that makes paper copies of documents and other visual images quickly and cheaply. Most current photocopiers use a technology called xerography, a dry process using heat...
. The speed of an FX/1 was about 2.5 MIPS (million instructions per second) and compared favorably to the 1 MIPS VAX-11/780. A fully populated eight CE FX/8, with eight times the aggregate MIPS, was in practice around five times faster than the FX/1 at solving problems that allowed a high degree of parallel computation (see Amdahl's law).
A second series of FX machines, introduced in early 1988, replaced the CE with new custom hardware known as the Advanced Computational Element (ACE). The Weitek FPUs were replaced by a floating point chipset made by Bipolar Integrated Technology
Bipolar Integrated Technology
Bipolar Integrated Technology was a semiconductor company based in Beaverton, Oregon which sold products implemented with ECL technology. The company was founded in 1983 by former Floating Point Systems, Intel, and Tektronix engineers. The company was later renamed BIT Inc..The initial product...
and a redesigned vector processor
Vector processor
A vector processor, or array processor, is a central processing unit that implements an instruction set containing instructions that operate on one-dimensional arrays of data called vectors. This is in contrast to a scalar processor, whose instructions operate on single data items...
with 32 64-bit vector elements, 8 64-bit scalar floating point registers, 8 32-bit integer registers, and 8 32-bit address registers. The new vector processor increased vector processing speed while reducing board space allowing the ACE to return to the 18x18 inch profile used by the other system boards in the main chassis. These were used in the FX/40, FX/80 and VFX machines.
1990s
In 1990, the FX/2800 series replaced the CE/ACEs and IPs with modules based on the Intel i860Intel i860
The Intel i860 was a RISC microprocessor from Intel, first released in 1989. The i860 was one of Intel's first attempts at an entirely new, high-end instruction set since the failed Intel i432 from the 1980s...
RISC chip. The i860 was an early superscalar
Superscalar
A superscalar CPU architecture implements a form of parallelism called instruction level parallelism within a single processor. It therefore allows faster CPU throughput than would otherwise be possible at a given clock rate...
CPU that allowed the programmer access directly into the pipelines; with custom coding the 860 was a very fast system, making it perfect for supercomputer
Supercomputer
A supercomputer is a computer at the frontline of current processing capacity, particularly speed of calculation.Supercomputers are used for highly calculation-intensive tasks such as problems including quantum physics, weather forecasting, climate research, molecular modeling A supercomputer is a...
applications. In the new series the Super Computational Element (SCE) and Super Interactive Processor (SIP) both consisted of up to four i860s, up to seven of which could be interconnected on the crossbar. A fully expanded FX/2800 could support 28 i860's in total.
Also in 1990 Alliant purchased Raster Technologies, a provider of high-resolution graphics
Graphics
Graphics are visual presentations on some surface, such as a wall, canvas, computer screen, paper, or stone to brand, inform, illustrate, or entertain. Examples are photographs, drawings, Line Art, graphs, diagrams, typography, numbers, symbols, geometric designs, maps, engineering drawings,or...
terminals and custom graphics cards for 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...
workstations. Their GX4000 product was a combination of PHIGS+
PHIGS
PHIGS is an API standard for rendering 3D computer graphics, at one time considered to be the 3D graphics standard for the 1990s. Instead a combination of features and power led to the rise of OpenGL, which became the most popular professional 3D API of the 1990s...
software and special graphical boards that could generate and display graphical vectors very fast. For 3D effects, a hardware Z-buffer was available. The Raster graphics technology was integrated with FX/40 and FX/80 machines to produce the VFX, Alliant's first fully integrated graphical minisupercomputer
Minisupercomputer
Minisupercomputers constituted a short-lived class of computers that emerged in the mid-1980s. As scientific computing using vector processors became more popular, the need for lower-cost systems that might be used at the departmental level instead of the corporate level created an opportunity for...
.
Alliant's final product series was the CAMPUS/800, a massively parallel machine based on units similar to the FX/2800 known as ClusterNodes and sharing a total of up to 4GB of unified memory. Each ClusterNode was connected to up to 32 others with an intra-ClusterNode switch, with a latency of 1us and 1.12GB/s bandwidth. An inter-ClusterNode switch based on HIPPI
HIPPI
HIPPI is a computer bus for the attachment of high speed storage devices to supercomputers. It was popular in the late 1980s and into the mid-to-late 1990s, but has since been replaced by ever-faster standard interfaces like SCSI and Fibre Channel.The first HIPPI standard defined a 50-wire...
was also available, with a latency of 30us and 2.56GB/s bandwidth. The largest CAMPUS system created included 192 ClusterNodes in total, and provided 4.7 GFLOPS.
The CAMPUS/800 was first announced in 1991, but the company was hit by a series financial problems and went bankrupt in 1992. Various Alliant systems soldiered on in service for many years after that however, and were generally considered very reliable.
The Computer History Museum
Computer History Museum
The Computer History Museum is a museum established in 1996 in Mountain View, California, USA. The Museum is dedicated to preserving and presenting the stories and artifacts of the information age, and exploring the computing revolution and its impact on our lives.-History:The museum's origins...
has examples of the FX/8 and FX/1 (from Convex Computer Corporation after Alliant's fall), but is seeking examples of FX/80 and FX/2800 configurations.