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Date: Wed, 20 Aug 1997 00:32:51 -0700 (PDT)
Organization: Atlas Telecom
From: Simon Shapiro <Shimon@i-Connect.Net>
To: (Curt Welch) <curt@kcwc.com>
Subject: Re: expected performance with DPT RAID-5...
Cc: scsi@FreeBSD.ORG, Tom Samplonius <tom@sdf.com>
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Hi Curt Welch;  On 18-Aug-97 you wrote: 
> Tom wrote:
> >  If I have 5 Barracuda 4LP 4GB drive (about 8MB/s raw
> >  read/write) on a single ultra wide channel on a DPT
> >  PM334/UW setup in a RAID-5 array, what kind of
> >  sequentional read/write performance should I expect?

About 8-9MB/Sec on READ, 5-6 on write.  Raid-5 is NOT optimal for
sequential access and WRITE performance degrades with number of
stripes.

> Don't know what to expect, but I have a similar config.
> 
> I have 5 Quantaum Atlas I 4G (fast wide) drives in a RAID-5
> config on one bus of of PM3334UW/2 and 5 Quantum Viking 4.55G
> (ultra wide) also in a RAID-5 config on the other bus.  The
> system is a 180MHz Pentium Pro with 128MB of memory.  The
> DPT has a full 64MB of cache (non ecc).
> 
> If you want me to run a test and tell you how it performs
> I will.  What type of test would you like to see?
> 
> BTW, the system still crashes every few days.  Don't know
> for sure if it's probelms with the system, the DPT or the
> DPT driver - I'm still working on it.  It was very stable
> before installing the DPT and the 10 new drives.

Are you still having problems?  What type?

Simon