The CDC 6600
While IBM was busy focusing on a wide swath of compatible systems with its System/360 line, a company called CDC had a different design goal for its next computer: fast and really fast.
Unshackled by any other considerations, such as compatibility or cost, Seymour Cray was free to use his legendary talents to focus on raw speed. He succeeded, as the roughly $7 million machine was the fastest computer from 1964 to 1969 by employing a unique design that relied on what would now be called an asymmetric multiprocessor design.
The main CPU ran at a blazing 10 MHz, but was very limited in the instructions it could perform, since it was in a very real sense a RISC processor long before the term was coined. It was capable of only very simple ALU functions, but was complemented by 10 logical peripheral processors that could do what the CPU could not, and kept it fed with data, while unfettering it from retiring data. The ability to make the processor more specialized and the parallelism by using the 10 "barrel" processors were key components in the exceptional performance of this machine. With an enormous amount of memory (128 K words), this 60-bit computer could trade off larger executable size for the additional performance that a simple instruction set could offer.
Although the CDC 6600 was a profitable machine, it was never a threat to the System/360’s market share–nor was it ever intended to be. Like our next machine, sometimes it was better to compete where IBM was not, rather than where it had targeted. The 6600 targeted a market higher than even the System/360 Model 75 could reach, while the next computer we look at targeted a market below where the System/360 Model 20 could.