Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!swrinde!mips!mash From: mash@mips.com (John Mashey) Newsgroups: comp.sys.m88k Subject: Re: Aviions -- How many MIPS can you get in a pizza box? Keywords: ... or maybe a pizza oven? Message-ID: <1288@spim.mips.COM> Date: 24 Mar 91 19:13:00 GMT References: <384@metran.UUCP> Sender: news@mips.COM Organization: MIPS Computer Systems, Inc. Lines: 37 Nntp-Posting-Host: winchester.mips.com In article <384@metran.UUCP> jay@metran.UUCP (Jay Ts) writes: ... >I have some figures from Data General quoting SPECmarks for their Aviions. >Unfortunately, they are apparently put relative to a VAX 11/780! I don't >understand SPECmarks well enough to understand what is going on here, but >anyway, here they are: > >machine: 300 310 >SPECmark: 8.7 10.2 > >Now, if anyone knows "official" SPECmark numbers for a VAX 11/780, please >post them! Yes. a VAX 11/780, with current compilers, is 1 SPECmark.... Note that SPECmark is a geometric mean of 10 benchmarks, 4 integer and 6 FP. If you believe mips are a measure of integer performance, then SPECint (the mean of the 4 integer benchmarks) is a better metric than Dhrystone... much better. Every computer architect knows that Dhryste overstates performance relae to the VAX more than real programs. In some sense, SPECint is about as good an approximation to vax-mips as you c get for lots of machines. The highest SPECint I've seen from DG (25MHz. 32KB cache, DG 6200) was 15.3. I saw some numbers from Motorola (25Mhz, 128KB, 8864SP) as high as 18.3. Tus, depending on compilers, memory system and such, one would expect thruput equivalant to 4X (SPECint for 1 CPU) - (adjustment for MP memory conflicts, which can range from a little to a lot). Bottom line: I conjecture that the 117-mips number is based on Dhrystone, even if it is labeled mips, rather than dhrystone-mips. I'd also conjecture that that number is 1.75-2X higher than a SPECint-based rating would give.... -- -john mashey DISCLAIMER: UUCP: mash@mips.com OR {ames,decwrl,prls,pyramid}!mips!mash DDD: 408-524-7015, 524-8253 or (main number) 408-720-1700 USPS: MIPS Computer Systems MS 1/05, 930 E. Arques, Sunnyvale, CA 94086