Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!uwm.edu!cs.utexas.edu!execu!sequoia!texbell!merch!cpe!adaptex!neese
From: neese@adaptex.UUCP
Newsgroups: comp.sys.ibm.pc
Subject: Re: Seagate ST01/02 SCSI Controllers --
Message-ID: <6100022@adaptex>
Date: 26 Oct 89 13:59:00 GMT
References: <5746@portia.Stanford.EDU>
Lines: 27
Nf-ID: #R:portia.Stanford.EDU:5746:adaptex:6100022:000:1461
Nf-From: adaptex.UUCP!neese    Oct 26 08:59:00 1989


>	Talk of st01 and st02 controllers has made me curious about my current 
>setup.  I have an ST-02 controller with and st296N 80meg seagate drive.
>The current transfer rate according to the core test is in the neighborhood 
>of 320k.  The drive also has REV 8 roms which I have heard are slower 
>than rev. 7 ones (it was slowed down for the MAC is the claim I have seen.)
>My question is What kind of performance can I expect if I can get rev 7 roms 
>for the drive? Also what about a better controller?  I plan to run UNIX 
>when I get the money so I was looking at the Adaptec controller.  Will it 
>work with the seagate drive?

The AHA-1540A/1542A will work with the Seagate drive.  Performance won't be
that great, but it will work.  I might as well throw this in while I am at
it.  The single biggest reason the ST02 card can't run the Seagate drive
at 1:1 interleave is the Seagate drive does not have a read ahead buffer on
it.  If it did, then 1:1 would be maintainable.  If you are looking for a
SCSI drive and want some performance, then you must look for drives that
have a read ahead buffer or else you can't maintain a 1:1 interleave, no
matter how fast the system is, as long as you use the ST02 card.  The 1540
can maintain a 1:1 interleave on drives that don't have a read ahead buffer,
so you would gain that.


			Roy Neese
			Adaptec Central Field Applications Engineer
			UUCP @ {texbell,attctc}!cpe!adaptex!neese
				merch!adaptex!neese