Path: utzoo!utgpu!watserv1!watmath!att!tut.cis.ohio-state.edu!zaphod.mps.ohio-state.edu!sdd.hp.com!hplabs!hpcc01!hpdmd48!sritacco
From: sritacco@hpdmd48.boi.hp.com (Steve Ritacco)
Newsgroups: comp.sys.dec
Subject: Re: Strange Disk Performance Help!
Message-ID: <15500017@hpdmd48.boi.hp.com>
Date: 11 Sep 90 15:46:53 GMT
Organization: Hewlett Packard - Boise, ID
Lines: 23

Hi,

After reading the posting about strange disk performance on the DECstation
I got pretty work up about the situation on my system.

I'm running a DECstation 2100 (UWS 2.1) with two MAXTOR LXT-213sy disks.

Running "time dd if=/vmunix of=/dev/null bs=8k" I'm only seeing about 
400K / second.  Is that all there is?  I got excited when I read the last
disk performance posting which mentioned SCSI_TRYSYNC which I didn't know
about.  My disks have a 32k read ahead cache and will opperate in 
synchronous mode.  I made the SCSI_TRYSYNC change to scsi_data and
rebuilt my kernel, but it didn't help.  Does anyone know what the
problem could be.  When I hear that new RZ55s are doing 1.5M/second on
the DECstations I get seriously upset.  Does anyone know how I can tell
if the disk is actually managing to run in sync mode.  Can anyone help?

If that is all the disk performance I'm going to get I would just like
to know so I can learn to live with it.  If UWS 4.0 will save me, I'd like
to know that too.  


HELP !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!