Date: Tue, 26 Aug 1997 22:10:16 -0700 (PDT) From: Simon Shapiro <Shimon@i-Connect.Net> To: Ollivier Robert <roberto@keltia.freenix.fr> Cc: current@FreeBSD.ORG Subject: Re: IDE vs SCSI was: flags 80ff works (like anybody doubted it) Message-ID: <XFMail.970826221016.Shimon@i-Connect.Net> In-Reply-To: <19970826082726.17963@keltia.freenix.fr>
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Hi Ollivier Robert; On 26-Aug-97 you wrote: > According to Jordan K. Hubbard: > > Hmmm. If we're going to talk SCSI perf, let's get seriously SCSI here > > then: Quantum XP39100W drive on 2940UW controller: > > > > root@time-> dd if=/dev/rsd0 of=/dev/null count=1600 bs=64k > > 1600+0 records in > > 1600+0 records out > > 104857600 bytes transferred in 10.974902 secs (9554309 bytes/sec) > > Aren't you disappointed ? You're only a mere 2 MB/s faster with a Wide > connection... I'd expect it more in the 14 MB/s range, no ? Not necessarily. Take a pencil in hand and compute from the specs. The disk will have to spin very fast and seek even faster to sustain that. Also, you will not see much difference between narow, wide and ultra, unless you do real long blocks (where the data phase becomes significant. I will have some more data soon. Simon
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