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Date: 	Mon, 8 May 1995 15:36:55 -0700 (PDT)
From: Tom Samplonius <tom@haven.uniserve.com>
To: "Justin T. Gibbs" <gibbs@estienne.CS.Berkeley.EDU>
cc: hackers@FreeBSD.org
Subject: Re: Is a 486 fast enough for SCSI? 
In-Reply-To: <199505082151.OAA02666@estienne.cs.berkeley.edu>
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On Mon, 8 May 1995, Justin T. Gibbs wrote:

> >  I've got a AMD486DX4100 with an Adaptec 2940 and two SCSI drives.  When 
> >I run iozone on one drive I get about 1.9MB/s, but when I run a iozone on 
> >each drive I get about .9 MB/s (roughly half).  Since the SCSI bus runs 
> >at 10MB/s per second, the limiting factor appears to be the CPU?  I 
> >thought PCI devices required very little CPU time?
> >
> >Tom
> 
> Do you have disconnection disabled on your devices?  I don't see anywhere
> neer this kind of performance drop off on my 2742 with two drives (One drive
> is 5MB/s the other is 2MB/s).  

  Yes, disconnection is enabled.

Tom