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). -- ------------------------------------------------------------------------------ My opinions are my own. Objects in mirror are closer than they appear. E-Mail route: ...!pyramid!garth!walter (415) 852-2384 USPS: Intergraph APD, 2400 Geng Road, Palo Alto, California 94303 ------------------------------------------------------------------------------