Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site ames.UUCP Path: utzoo!watmath!clyde!burl!ulysses!petrus!bellcore!decvax!decwrl!Glacier!well!ptsfa!dual!ames!eugene From: eugene@ames.UUCP (Eugene Miya) Newsgroups: net.arch Subject: Re: RISC and MIPS Message-ID: <1093@ames.UUCP> Date: Mon, 19-Aug-85 12:33:02 EDT Article-I.D.: ames.1093 Posted: Mon Aug 19 12:33:02 1985 Date-Received: Sat, 24-Aug-85 13:28:27 EDT References: <419@kontron.UUCP> <2300001@uicsl> Organization: NASA-Ames Research Center, Mtn. View, CA Lines: 28 I have been following this discussion for some time. So what's the bottom line? If architecture is your thing, the proof of the putting are going to be running systems. The critics of RICS then focus their attack on a definition of MIPS. We've had two (or more) "What is a MIP letter?" in addition to the original one. A couple of years ago just before the Winter Usenix conference, I saw the Massively Parallel Processor (MPP). It is rated at peak speed of 16 billion instructions per second (16 GIPS). Now they only add later that this is an 8-bit word with 1-bit serial data paths. It burns me up when recently I saw a television ad that Goodyear Aerospace did this `great' thing for NASA at the cost of 10 million dollars. {oops, sorry, got out of hand, flame off} A problem is, certainly, how we measure things. One letter brought out the need to define what an instruction was. The letter did not specifically mention a property by name: that was `atomicity.' Another problem is a common base set of units: is there an appropriate conversion factor of a 64-bit instruction to an 8-bit? Is a factor of 8 good enough, probably not. Let's keep "standards" out of the discussion for now, and explore this a bit. Whetstones were mentioned in another letter, but the only people who use these are computer manufacturers. [MGT]FLOPS are another gastly measure. What qualities do our performance metrics need to have? --eugene miya NASA Ames Research Center {hplabs,ihnp4,dual,hao,decwrl,allegra}!ames!aurora!eugene emiya@ames-vmsb