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From: brooks@vette.llnl.gov (Eugene Brooks)
Newsgroups: comp.arch
Subject: Re: What kinds of problems...
Message-ID: <22171@lll-winken.LLNL.GOV>
Date: 19 Mar 89 21:46:53 GMT
References: <471@estevax.UUCP> <15347@winchester.mips.COM> <7137@phoenix.Princeton.EDU> <24888@amdcad.AMD.COM> <11458@cgl.ucsf.EDU>
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Reply-To: brooks@maddog.llnl.gov (Eugene Brooks)
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In article <11458@cgl.ucsf.EDU> seibel@cgl.ucsf.edu (George Seibel) writes:
>|| Are there any really big jobs out there that are seriously bounded
>|| by integer CPU performance?  (Excuse me, but I'm probably very naive)
>|
>|Oh, yes.  Our machines here are loaded with simulations to do.  We could
>|always use more integer performance.
>
>What kinds of simulations are these?   I don't doubt that they exist,
>I've just never seen one and am genuinely curious.   Would there be any
>commercial interest in a really fast integer box that had only fair
>floating pt performance?

Any computer architecture simulations are bound by integer performance.
There are quite a few companies which simulate their architectures before
they build them to evaluate the impact of instruction set and timing changes.
We simulated a full shared memory multiprocessor which used packet switched
networks for the shared memory system, doing algorithm/architecture studies,
and kept a Cray class processor busy for the better part of a year before the
workload ramped down.  For these programs software emulation of floating point
would have been sufficient. Of course the computer was used for other things
which required balanced floating point performance as well...


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