The CDC 8600 was the last of Seymore Cray's supercomputer designs while working for Control Data. The "natural successor" to the CDC 6600 and CDC 7600, the 8600 was intended to be about 10 times as fast as the 7600, already the fastest computer on the market. Development started in 1968, shortly after the release of the 7600, but the project soon started to bog down. By 1971 CDC was having cash flow problems and the design was still not coming together, prompting Cray to leave the company in 1972. The 8600 design effort was eventually cancelled in 1974, and Control Data moved on to the CDC STAR-100 series instead. Seymour Roger Cray (September 28, 1925 - October 5, 1996) was a supercomputer architect who founded the company Cray Research. ... A supercomputer is a computer that leads the world in terms of processing capacity, particularly speed of calculation, at the time of its introduction. ... Control Data Corporation, or CDC, was one of the pioneering supercomputer firms. ... The CDC 6600 was a mainframe computer from Control Data Corporation, first manufactured in 1965. ... The CDC 7600 was the Seymour Cray-designed successor to the CDC 6600, extending Control Datas dominance of the supercomputer field into the 1970s. ... The STAR-100 was a supercomputer from Control Data Corporation, one of the first machines to use a vector processor for improved math performance. ...

In the 1960s computer design was based on mounting electronic components (transistors, resistors, etc.) on circuit boards. Several boards would be used up to make a discrete logic element of the machine, known as a "module". As computer power increased the complexity of the modules did too, and even a single faulty part or soldier joint would render the entire module inoperative. Cray was well known in the industry for making seemingly impossibly complex modules work. Through hole transistors (tape measure marked in centimeters) The transistor is a solid state semiconductor device which can be used for amplification, switching, voltage stabilization, signal modulation and many other functions. ... Resistor symbols A resistor is a two-terminal electrical component that creates an electrical potential difference across its terminals that is proportional to the current passing through it. ... Close-up photo of one side of a motherboard PCB, showing conductive traces, vias and solder points for through-hole components on the opposite side. ...

Overall machine "cycle speed" is strongly related to the signal path -- the length of the wiring -- forcing high speed computers to make their modules as small as possible. This was at odds with the need to make the modules themselves more complex to increase computing power. By the late 1960s individual components had stopped getting much smaller, and although integrated circuits addressed the size issue, their simple MOSFET-based technology didn't have the performance needed for high-speed applications. So in order to increase the complexity of the machines, the modules would have to grow. An integrated circuit (IC) is a thin chip consisting of at least two interconnected semiconductor devices, mainly transistors, as well as passive components like resistors. ... The MOSFET, or Metal-Oxide-Semiconductor Field-Effect Transistor, is by far the most common field effect transistor in both digital and analog circuits. ...

Cray aimed to solve these contradictory problems by doing both; making each module larger and crammed with many more components, while at the same time making the computer as a whole smaller by packing the modules closer together inside the machine. In the case of the 8600, this led to modules containing eight four-layer circuit boards about 8" by 6", resulting in a stack the size of a large textbook and using up about 3 kilowatts of power.

Cooling the modules proved to be a major problem. Cray's refridgeration engineer, Dean Roush, formerly of Amana, placed a sheet of copper inside each of the circuit boards, removing the heat to a copper block on one end where it was cooled by a freon system. This further increased the weight and complexity of the modules, to the point where each one weighed about 15 pounds. The modules were then packed into a mainframe chassis that was comparatively tiny, a 16-sided cylinder about one meter across and high, sitting on top of a ring of power supplies. The external cooling system was considerably larger than the machine itself. Perhaps unsurprisingly, the 8600 bears a strong resemblance to the later Cray-2. Categories: Hebrew Bible/Tanakh-related stubs | Hebrew Bible/Tanakh places ... Freon is a trade name for a group of chlorofluorocarbons used primarily as a refrigerant. ... The Cray-2 is in the left foreground. ...

The components themselves were likewise improved over previous designs. The main CPU circuits moved to ECL-based logic, allowing the clock speed to be increased to 8 ns (120MHz) from the 7600's 27.5 -- an increase of about four times. Main memory was also moved to an ECL implementation and the machine was equipped with a whopping 256k-words (2 megabytes) standard. The memory was spread across 64 banks storing one bit of a word each, thereby allowing fast access at about 8 ns/word even though the cycle time of any one bank was about 250 ns. A high-speed core memory with a 20 ns access (overall) was also designed as a backup to the semiconductor version. This CPU uses numerous pins to connect to the motherboard. ... In electronics, emitter coupled logic (or ECL) is a design which uses transistors to steer current through gates which compute logical functions. ... A 16×16 cm area core memory plane of 128×128 bits, i. ...

As if this were not enough, Cray decided that the 8600 would include four complete CPUs sharing the main memory. In order to improve overall throughput, the machine could be operated in a special mode in which a single instruction was sent to all four processors with different data. This technique, today known as SIMD, reduded the total number of memory accesses because the instruction was only read once, instead of four times. Each processor was about 2.5 times as fast as a 7600, so with all four running the machine as a whole would be about 10 times as fast, at about 100 MFLOPS. Primary storage is a category of computer storage, often called main memory. ... In computing, SIMD (Single Instruction, Multiple Data) is a set of operations for efficiently handling large quantities of data in parallel, as in a vector processor or array processor. ...

The 8600 was the first CDC design to move to ASCII-based processing, and therefore used a 64-bit word instead of the earlier 60-bit word used on the 6600 and 7600. As in prior designs, instructions were "stuffed" into words, with each instruction taking up either 16 or 32 bits (up from 15/30). The 8600 no longer used the A or B registers as in previous designs, and included a set of 16 general-purpose X registers instead -- making the 8600 even more RISC-like than the 6600 or 7600. A 6600/7600 Peripheral Processor system was used for I/O, largely unchanged. There are 95 printable ASCII characters, numbered 32 to 126. ... In computing, a 64-bit component is one in which data are processed or stored in 64-bit units (words). ... Reduced Instruction Set Computing (RISC), is a microprocessor CPU design philosophy that favors a smaller and simpler set of instructions that all take about the same amount of time to execute. ... This article is about the computer interface. ...

In 1971 Control Data was undergoing a "belt tightening" due to the cost of an ongoing lawsuit against IBM, and all divisions were asked to reduce their payroll by 10%. Cray begged to be exempted in order to get the 8600 shipping, and when this request was refused he instead had his own pay cut to minimum wage to solve the problem. International Business Machines Corporation (IBM, or colloquially, Big Blue) (NYSE: IBM) (incorporated June 15, 1911, in operation since 1888) is headquartered in Armonk, NY, USA. The company manufactures and sells computer hardware, software, and services. ... The minimum wage is the minimum rate a worker can legally be paid (usually per hour) as opposed to wages that are determined by the forces of supply and demand in a free market. ...

By 1972 it appeared that even Cray's ledgendary module design abilities were failing him in the case of the 8600. Reliability was so poor that it was appeared impossible to get a whole machine working. This was not the first time this had happened, on the 6600 project Cray had to start over from scratch, and the 7600 was in production for some time before it started working reliably. In this case Cray decided the current design was a dead-end, and told William Norris (CDC's CEO) that the only way forward was to redesign the machine from scratch. The finances of the company were dangerous, and Norris decided that he couldn't take the risk; Cray would have to continue with the current design. The CDC 6600 was a mainframe computer from Control Data Corporation, first manufactured in 1965. ... For other people named William Norris see William Norris (disambiguation). ...

In 1972 Cray decided that he couldn't work under such conditions, and left CDC to form Cray Research. For his new work he abandoned the multiprocessor concept, concerned that software of the era would be unable to take full advantage of the CPUs. He may have come to this conclusion after the ILLIAC IV finally entered operation at about the same time, and proved to have disappointing performance. Cray-2 supercomputer Cray Inc. ... The ILLIAC IV was one of the most infamous supercomputers ever, destined to be the last in a series of research machines from the University of Illinois. ...

Someone managed to convince Norris that the 8600 could be completed even without Cray, and work continued at the Chippewa Lab. By 1974 the machine still didn't work right. Jim Thornton's competing STAR design had reached production quality at this point, and the 8600 project was then cancelled. In service STAR proved to have poor real-world performance, and when the Cray-1 entered the market in 1976, CDC was quickly pushed from the supercomputer market. An effort was made to re-enter the market in the 1980s with the ETA-10, but this ended poorly. The STAR-100 was a supercomputer from Control Data Corporation, one of the first machines to use a vector processor for improved math performance. ... CRAY-1 at the EPFL in Switzerland. ... An ETA-10 supercomputer installation The ETA-10 was a line of supercomputers manufactured by ETA Systems (a spin-off division of CDC) in the 1980s and which implemented the instruction set of the CDC Cyber 205. ...

Notes

• Gordon Bell puts the project start at 1968, while other sources suggest 1970.

• Quoted memory speed varies widely, with some sources suggesting a 22 ns cycle time for the semiconductor and 20 ns for the core, while other suggest the higher numbers used in this article.