Path: utzoo!attcan!uunet!lll-winken!lll-tis!helios.ee.lbl.gov!pasteur!ames!zodiac!joyce!sri-unix!garth!walter
From: walter@garth.UUCP (Walter Bays)
Newsgroups: comp.arch
Subject: Re: RISC bashing at USENIX
Message-ID: <936@garth.UUCP>
Date: 12 Jul 88 17:36:20 GMT
References: <6888@ico.ISC.COM> <11496@steinmetz.ge.com> <6965@ico.ISC.COM>
Reply-To: walter@garth.UUCP (Walter Bays)
Organization: INTERGRAPH (APD) -- Palo Alto, CA
Lines: 26

Several articles recently have commented that Neal Nelson (benchmark
service) is challenging the widely held view that RISC is faster than
CISC, saying that CISC is faster than RISC.  NN's most famous
comparison shows that a Sun 3 is faster than a Sun 4.  The other side
can cite benchmarks showing that a Sun 4 is much faster than a Sun 3.

An article in the July issue of UNIX Review sheds some light on the issue.
It's by David Wilson of Workstation Laboratories (another benchmark service).
The article shows "... a class of tasks for which the Sun 4/260 is two or
three times faster than the Sun 3/260, a class for which performance is about
the same, and a class where the 4/260's performance seems slightly lower..."
Wilson discusses the reasons for these results.

Any computer designer selects architectural features based on their
expected utility given the class of workloads to be run.  RISC arose
from the observation that many of the features of conventional
computers did not help (or hurt) performance _in_ _the_ _typical_
_case_.  Various CISC's have always included several RISC-like features
their designers found helpful.  And most RISC's include a few CISC-like
features their designers found helpful.  For performance comparisons,
there is no subtitute for a benchmark that represents your application(s).
-- 
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