Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!usc!cs.utexas.edu!evax!utacfd!merch!cpe!adaptex!adaptx1!neese
From: neese@adaptx1.UUCP
Newsgroups: comp.periphs.scsi
Subject: Re: Low disk throughput on Xenix 2.3.2/
Message-ID: <283400078@adaptx1>
Date: 19 Mar 91 06:58:04 GMT
References: <20092@simasd.uucp>
Lines: 26
Nf-ID: #R:simasd.uucp:20092:adaptx1:283400078:000:1078
Nf-From: adaptx1.UUCP!neese    Mar 18 11:10:00 1991


>	I am having a problem with SCO Xenix 2.3.2GT and very low disk
>transfer rates.  Here is my configuration:
>33 MHz 386 w/387
>8 Meg ram
>128K cache
>Adaptec 1542B DMA=5 irq=11 i/o base=330, bios enabled, 5 Meg DMA transfer rate
>Wren V 330 Meg SCSI drive
>Archive 2150S tape drive
>Digiboard Com8/i Serial card
>WD8003 ethernet card
>With this config, I am only able to get 124K Bytes/sec. throughput under
>Xenix.  Under Dos I get 496 K Bytes/sec.  Under ISC Unix, similar rates
>to Dos.  Is there a known problem with the scsi drivers under Xenix?
>Why would throughput be so low?  Running the same config except for the
>drives and controller (substitue in a wd1003 controller and Maxtor 2190)
>gave me double the disk throughput.  Why???

Get the xnx252 driver from SCO or adaptex.  You will see a performance gain.
You could also check to see of the read ahead cache is enabled in the drive
via SCSICNTL.  If it isn't, try enabling it.

			Roy Neese
			Adaptec Senior SCSI Applications Engineer
			UUCP @  neese@adaptex
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