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From: mitchalsup@aol.com (MitchAlsup1)
Newsgroups: comp.arch
Subject: Re: what's a mainframe, was is Vax addressing sane today
Date: Wed, 11 Sep 2024 21:15:29 +0000
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On Wed, 11 Sep 2024 16:21:19 +0000, John Levine wrote:

> According to Anton Ertl <anton@mips.complang.tuwien.ac.at>:
>>Lawrence D'Oliveiro <ldo@nz.invalid> writes:
>
> The 360/91 was also intended to be the fastest possible computer, which
> again it sort of
> was, late and over budget. One thing that STRETCH and the /91 shared was
> that they were
> extremely complicated. STRETCH had variable sized bytes and and
> addressing modes that I
> never entirely figured out. The /91 had an instruction queue with loop
> mode and out of
> order operations and register renaming and imprecise interrupts. When
> the CDC 6600 came
> out, a much simpler design from a tiny company that was nonetheless
> faster than the /91,
> they knew they had a problem. The /95 and /195 were minor upgrades of
> the /91 but that was
> the end of their supercomputer efforts.

You forgot to mention /91 had a 60ns clock while 6600 had a 100 ns
clock.
Here was a case where parallelism beat out pipelining.