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From: pf@diab.UUCP (Per Fogelstrom)
Newsgroups: comp.arch
Subject: Re: What with these Vector's anyways?
Message-ID: <279@diab.UUCP>
Date: Wed, 29-Jul-87 03:54:17 EDT
Article-I.D.: diab.279
Posted: Wed Jul 29 03:54:17 1987
Date-Received: Sat, 1-Aug-87 15:55:31 EDT
References: <218@astra.necisa.oz> <142700010@tiger.UUCP> <363@astroatc.UUCP> <8344@utzoo.UUCP> <3636@well.UUCP> <10956@amdahl.amdahl.com>
Sender: news@diab.UUCP
Reply-To: pf@.UUCP (Per Fogelstrom)
Distribution: world
Organization: Diab Data AB, Taby, Sweden
Lines: 30
Keywords: scalar vs. vectors, benchmarks
Summary: Benchmarks ???

In article <10956@amdahl.amdahl.com> littauer@amdahl.UUCP (Tom Littauer) writes:
>In article <3636@well.UUCP> rchrd@well.UUCP (Richard Friedman) writes:
>>The best supercomputers are fast scalar machines first, with vector
>>processing hardware for additional speedup.  Machines like the Cray X-MP
>>have a vector-to-scalar speedup factor of about 10.  But their scalar
>>performance is faster than any conventional machine.  
>                !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
>
>If the Dhrystone benchmarks are to be believed, this isn't the case.
>The May '87 report shows Cray X-MP at 18,530, and the IBM 3090-200
>at 31,250. I'd mention our (much faster) machines, but that'd get
>perilously close to advertising :-).
>

Be serious! Do you really belive in Dhrystone? Okay i do admitt that we don't
have anything better for the moment, but soon i hope.

What this benchmark really tests is the compilers ability to remove code that
does'nt really do anything. And of course the cpu's ability to handle strings.
Just check the Am29000. The designers put in an instruction just to speed up
this benchmark.... Now what, have we reaced a new point, where cpu's are
designed for the bencmarks instead of vice versa, as it was before ????

[ There are three types of lie, lie, damned lie, and BENCHMARKS !! ]

-- 
Per Fogelstrom,  Diab Data AB
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