CDC 8600
The CDC 8600 was the last of Seymour Cray's supercomputer designs while he worked for Control Data Corporation. As 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. The design was essentially four 7600's, packed into a very small chassis so they could run at higher clock speeds.
Development started in 1968, shortly after the release of the 7600, but the project soon started to bog down. The dense packaging of the system led to serious reliability problems and difficulty cooling the individual components. 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 canceled in 1974, and Control Data moved on to the CDC STAR-100 series instead.
Cray revisited the 8600's basic design in his Cray-2 of the early 1980s. The introduction of integrated circuits solved the problems with dense packaging and liquid cooling addressed the heat issues. The Cray-2 is very similar to the 8600 both physically and conceptually.