Path: utzoo!attcan!uunet!lll-winken!lll-tis!ames!amdahl!sri-unix!garth!walter From: walter@garth.UUCP (Walter Bays) Newsgroups: comp.arch Subject: Re: Dhrystone compilation times Message-ID: <677@garth.UUCP> Date: 22 May 88 05:49:43 GMT References: <5213@ico.ISC.COM> Reply-To: walter@garth.UUCP (Walter Bays) Organization: INTERGRAPH (APD) -- Palo Alto, CA Lines: 28 Posted: Sat May 21 22:49:43 1988 In article <5213@ico.ISC.COM> rcd@ico.ISC.COM (Dick Dunn) writes: >I found an extreme case where, on the actual [Dhrystone 2.0] >benchmark, machine A was about 80% of the Dhrystones of machine B; however, >the time (user CPU) to do the "make" on machine B was 5 TIMES what it was ^^^^^^^ >on machine A! ^^^^^^^ Really machine + compiler + optimization level. Changing any of the three can make an order of magnitude or more difference. Your example points out the very different needs of development and production environments. >In particular, if you're looking for a fast >machine where you're going to do a lot of development, it would be a bad >mistake to look at the Dhrystone number and think that machine B above >would be better than A, or even comparable. True in any case. Use Dhrystones to compare one MS-DOS PC against another with identical compilers, or one Mac against another with identical compilers, or one compiler against another on the same machine. Use Dhrystones to choose workstations "in the same ballpark" to look at more closely. Don't use them to completely characterize the differences between two machines or compilers. -- ------------------------------------------------------------------------------ The U.S. is to space exploration Any similarities between my opinions as Portugal was to sea exploration. and those of the person who signs my paychecks is purely coincidental. E-Mail route: ...!pyramid!garth!walter (415) 852-2384 USPS: Intergraph APD, 2400 Geng Road, Palo Alto, California 94303 ------------------------------------------------------------------------------