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Xref: sserve comp.os.linux:39572 comp.os.386bsd.questions:2571 comp.unix.pc-clone.32bit:2870 Newsgroups: comp.os.linux,comp.os.386bsd.questions,comp.unix.pc-clone.32bit Path: sserve!newshost.anu.edu.au!munnari.oz.au!news.Hawaii.Edu!ames!elroy.jpl.nasa.gov!decwrl!lll-winken.llnl.gov!fastrac.llnl.gov!wsrcc.com!wetware!spunky.RedBrick.COM!psinntp!psinntp!fstalb!mooreb From: mooreb@fac.com (Brian Moore) Subject: Re: IDE vs SCSI and performance Organization: First Albany Corp. Date: Wed, 19 May 1993 18:02:14 GMT Message-ID: <1993May19.180214.7745@fac.com> References: <C72CAw.B47@sugar.NeoSoft.COM> <1993May17.190905.3462@gandalf.ca> <C78rG8.707@rex.uokhsc.edu> Lines: 31 In article <C78rG8.707@rex.uokhsc.edu> benjamin-goldsteen@uokhsc.edu writes: >ykhan@gandalf.ca (Yousuf Khan) writes: > >>In <C72CAw.B47@sugar.NeoSoft.COM> peter@NeoSoft.com (Peter da Silva) writes: > >>>I was talking to a fellow in a computer store the other day, and he was >>>insisting that he was getting 2.5 MB/s on his IDE drives under AmigaOS, >>>over twice what he got with SCSI. > >I wouldn't really say that... Quite a few of the high-end drives are >actually rather decent. I have a reference for a MO disk system that >sustains 12MBytes/second (I have no idea how much this costs...) > >Low-end SCSI's versus IDE might be about the same... Well, looking through the specs on the Conner CP3364's we have here at work, they show a media transfer rate of 2.5 MB/sec. It isn't really all that difficult to get that. The drive spins at 4500 RPM, or 75 RPsec. With a 1:1 interleave, it can read a full track in one revolution. I don't know what sort of effect the 3 msec track-to-track seek time will have, as I don't know if the drive uses track skewing. I'll assume it has decent track skewing, and that it can read 61 tracks/sec (with 183 msec overhead for seeks). At 49 sectors per track, that's about 3000 sectors or 1.5 MB it can read per second at a sustained rate. If the drive has more sectors on the outside tracks, then it might get up ot 2.5 MB/sec. Of course you rarely get any application that just reads a huge file. -- Brian Moore, mooreb@fac.com | I wrote up a nice script to truncate all News& First Albany Corp. Sysadmin | Mail sigs that are greater than 4 lines long. standard disclaimers apply | It is still in beta testing due to an off-by-