Date: Mon, 9 Oct 1995 16:31:42 +0100 From: se@zpr.uni-koeln.de (Stefan Esser) To: "Jonathan M. Bresler" <jmb@kryten.atinc.com> Cc: hackers@freebsd.org Subject: Re: VLB Disk Controllers Message-ID: <199510091531.AA00468@Sysiphos> In-Reply-To: "Jonathan M. Bresler" <jmb@kryten.atinc.com> "Re: VLB Disk Controllers" (Oct 8, 18:01)
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On Oct 8, 18:01, "Jonathan M. Bresler" wrote:
} Subject: Re: VLB Disk Controllers
} On Mon, 9 Oct 1995, Bruce Evans wrote:
Seems you got disk_latency.c meanwhile ...
(Didn't go to work on Sunday, so I couldn't reply earlier :)
} > >> > transfer speed is 1.25286e+07 bytes/sec
} >
} > >heh?
} > >how do you get 12MB/sec on a 10MB/sec SCSI bus?
}
} well how about these numbers (dont sweat them, i have not yet
} created the sd1sX devices)
}
} ./disklatency /dev/rsd1f
} Command overhead is 11092 usec (time_4096 = 11098, time_8192 = 11104)
} transfer speed is 6.88982e+08 bytes/sec
} Aspen: {258} !!
} ./disklatency /dev/rsd1f
} Command overhead is 6270 usec (time_4096 = 4104, time_8192 = 1938)
} transfer speed is -1.891e+06 bytes/sec
} Aspen: {259} !!
} ./disklatency /dev/rsd1f
} Command overhead is 10991 usec (time_4096 = 11098, time_8192 = 11204)
} transfer speed is 3.84637e+07 bytes/sec
} Aspen: {260} !!
} ./disklatency /dev/rsd1f
} Command overhead is 11065 usec (time_4096 = 11120, time_8192 = 11175)
} transfer speed is 7.4424e+07 bytes/sec
What controller is that ?
11ms seems very long, but that is what I got on our Sparc10 servers
running SunOS 4.1.3 as well (on 4GB Barracuda II drives !)
STefan
--
Stefan Esser, Zentrum fuer Paralleles Rechnen Tel: +49 221 4706021
Universitaet zu Koeln, Weyertal 80, 50931 Koeln FAX: +49 221 4705160
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