Path: utzoo!attcan!uunet!cs.utexas.edu!usc!rutgers!mcnc!uvaarpa!murdoch!astsun.astro.Virginia.EDU!gl8f From: gl8f@astsun.astro.Virginia.EDU (Greg Lindahl) Newsgroups: comp.sys.atari.st Subject: Re: DHRYSTONE Message-ID: <1990Jun15.194338.8548@murdoch.acc.Virginia.EDU> Date: 15 Jun 90 19:43:38 GMT References: Sender: news@murdoch.acc.Virginia.EDU Organization: Department of Astronomy, University of Virginia Lines: 24 In article larserio@IFI.UIO.NO (LarsErikOsterud) writes: >The version of DHRY.TTP posted on comp.binaries must be insane... >It give 630 on a standard ST and 1300 on a 16 Mhz ST, but all tests >made by ST freaks here shows over 1000 on a standard ST ??? Different compilers give different Dhrystone ratings depending on how agressive their optimization is. Dhrystone does some very strange things, including copying constant strings into word-aligned buffers. Compilers can "cheat" on this by turning strcpy() into a simple loop. As a result, you can get results as high as 1500 on a standard ST. There are some very interesting and real differences between compilers, but it's hard to use Dhrystone to find which one is the best. Dhrystone is useful to compare the same processor at different clock speeds, but use the same compiler. For example, if you want to compare the speeds of various ST's and Amigas, you could use gcc to compile Dhrystone, and then you would be looking at only the hardware difference, not compilers that may be using optimizations great for Dhrystone but useless for real code. -- "Perhaps I'm commenting a bit cynically, but I think I'm qualified to." - Dan Bernstein