Re: The Seymour Cray Era of Supercomputers

On Mon, 19 May 2025 1:56:50 +0000, Lawrence D'Oliveiro wrote:

On Mon, 19 May 2025 01:08:11 +0000, quadibloc wrote:
>

Yes, but the CDC 6600 and 7600, while powerful computers, were ordinary
computers. They were not vector machines.

>
They were pipelined machines. They were orders of magnitude faster than
anything from IBM. They pioneered the very concept of a “supercomputer”.
>
There was nothing “ordinary” about that.

Yes, that is a fair comment. Eventually, IBM caught up with the Control
Data 6600 by perfecting pipelining in the IBM 360/91, and then combining
it with cache in the 360/195. From the Pentium II onwards, that's the
way computers are made nowadays.
I didn't mean to belittle the 6600, but simply to note that it lacked
the additional speedup that you get from having a vector machine.
Whereas the STAR-100 and the ASC had the opposite fault: having vectors
was all those machines had going for them, while their scalar portions,
unlike that of the 6600, were very definitely ordinary - and so Amdahl's
Law bit them, as I noted.
John Savard