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Xref: sserve comp.unix.bsd:7502 comp.os.linux:14857 Path: sserve!manuel.anu.edu.au!munnari.oz.au!uniwa!uniwa!nfm From: oreillym@tartarus.uwa.edu.au (Michael O'Reilly) Newsgroups: comp.unix.bsd,comp.os.linux Subject: Re: IDE faster than SCSI-2 Date: 7 Nov 1992 09:50:50 +0800 Organization: Home Lines: 33 Message-ID: <1df7dqINN37o@tartarus.uwa.edu.au> References: <1992Nov5.080716.10386@ntuix.ntu.ac.sg> NNTP-Posting-Host: tartarus.uwa.edu.au X-Newsreader: TIN [version 1.1 PL6] Othman Ahmad (eoahmad@ntuix.ntu.ac.sg) wrote: : I posted an iozone benchmark using my 386/25Mhz machine which shows that : it is slightly slower than a SCSI-2 hard-disk. Now with a 486/33, IDE is : definitely faster than a EISA SCSI-2 486/50MHZ hard-disk. : Iozone uses normal unix system calls for writing to disks, after all, : that is how we write C programs. : I may try to run a more sophisticated file system tester called : bi? later on. : : : JUlian's machine : is a 50MHz EISA 486 with a 1.3GB drive attached via a Bustek 742a SCSI2 : adapter. It has 16MB of ram. Part of the disk (about 200MB is taken up : by mach2.6 and is unavailable to 386bsd. : : I checked the load on this machine, it is very light. There is only another : user apart from I. : : iozone 1 : : Writing the 1 Megabyte file, 'iozone.tmp'...1.766667 seconds ^ ^ This is useless. It tells no-one anything. A one meg file should fit entirely in the cache. So unless BSD is braindead, and doesn't cache (which I doubt), then you have just measured the cache speed. On my 486/33, 8 meg ram, a 1 meg files get 10 megs per second. The disk is never accessed, unless a sync kicks in 1/2 way though. I don't know exactly what you measured, but it sure ain't disk speed. : Othman bin Ahmad, School of EEE, : Michael