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Newsgroups: comp.os.386bsd.bugs Path: sserve!newshost.anu.edu.au!munnari.oz.au!news.Hawaii.Edu!ames!saimiri.primate.wisc.edu!usenet.coe.montana.edu!osyjm From: osyjm@cs.montana.edu (Jaye Mathisen) Subject: Re: IOZONE results Message-ID: <1993Mar18.212127.21263@coe.montana.edu> Sender: usenet@coe.montana.edu (USENET News System) Organization: CS References: <C43MBo.3owM@austin.ibm.com> Date: Thu, 18 Mar 1993 21:21:27 GMT Lines: 44 In article <C43MBo.3owM@austin.ibm.com> fredriks@austin.ibm.com (Lars Fredriksen) writes: > > >Hi, > This is not a bug per se, as much as a request to see what >other people are seeing. > > I ran iozone auto on my machine and got the maximum of 500K/s >throughtput. I saw a report from someone running Interactive Unix on >a 50MHz 486 with a Bustek controller getting 4.5M/s. > > My machine is a 33MHz 486 with 128K of cache, 16Mb of Memory, > with an Adaptec 174x controller. I have Julians scsi drivers, > and the drive is supposed to be capable of 5M/s. > >Anyone have a clue to why I am seeing a factor of 10 difference? > >Where/how does the kernal determine who big of a buffer cache to use? I just spend a fair amount of time with benchmarking some i/o stuff with IOZONE: Machine: DECPC 486/50 (not dx2),EISA,2 Adaptec 1740's,DEC RZ25,Fuji 2624. OS: 386BSD 0.1 with patchkit 2.1 and 84-110. Most of my performance varied with the block/frag sizes and some tweaking with tunefs, but the upshot was: 4k/512byte, read:230k, write 250k. 8k/2k,tunefs -a 8 read:1.7M, write 1.3M. The difference in speeds between the DEC drive and the Fuji drive wasn't much. But the DEC was faster in all cases. Any combination that I tried (and I think I tried all combo's of 2k-8kblocks, and 512byte to 2k frags) other than 8k/2k were well under 700k/second. I didn't try 16k block sizes, I don't know if they're supported. So, check your disk partitioning. your mileage may vary. -- Jaye Mathisen, COE Systems Manager (406) 994-4780 410 Roberts Hall,Dept. of Computer Science Montana State University,Bozeman MT 59717 osyjm@cs.montana.edu