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From: romero@parc.xerox.com (Antonio Romero)
Newsgroups: comp.sys.next
Subject: Re: Benchmarks
Message-ID: <1991Jan8.231145.3537@parc.xerox.com>
Date: 8 Jan 91 23:11:45 GMT
References: <10016@pasteur.Berkeley.EDU> <1991Jan5.022126.19747@percy.rain.com>
Sender: news@parc.xerox.com
Organization: Xerox PARC
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In article <1991Jan5.022126.19747@percy.rain.com> nerd@percy.rain.com (Michael Galassi) writes:
>In article <10016@pasteur.Berkeley.EDU> jclee@cory.Berkeley.EDU (James C. Lee) writes:
>>> The NeXTStation was about 20-30% faster on this group of benchmarks
>>> than the DECStation 3100.  This is surprising since the DECStation is
>>> rated and 13.9 Mips and the NeXTstation benches at 15.0 Mips.  You
>>> would expect from the Mips rating only about a 10% increase.

>MIPS = Milions of Instructions Per Second.  An 040 does more in each
>average instruction than the MIPS R[23]000 (in the DECstations) 
>...  It folows that no usefull information can be gotten by
>comparing MIPS figures for processors of different families.

Nope, 'fraid not...  MIPS these days have been normalized to make 1 MIPS=
some canonical VAX 11/780 somewhere.

This is not to suggest that useful information can be gotten from
hype-sheet MIPS figures, but they're inaccurate because people tweak
the tests that generate the numbers to take advantage of on-chip caches,
unusually fast instructions unique to that chip, etc., not because the
processors do different amounts of work per instruction.

MIPS ratings are notoriously bogus.  Does anyone know if the SPECMARK is
any better, or if it's susceptible to the same sort of cheating that
more traditional benchmarks suffer from?

-Antonio Romero         romero@arisia.xerox.com