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From: agnew@trwrc.UUCP (R.A. Agnew)
Newsgroups: comp.sys.ibm.pc
Subject: Re: Vendor Recommendation (was: Building a UNIX system)
Message-ID: <223@trwrc.UUCP>
Date: Tue, 15-Sep-87 13:19:12 EDT
Article-I.D.: trwrc.223
Posted: Tue Sep 15 13:19:12 1987
Date-Received: Thu, 17-Sep-87 06:46:31 EDT
References: <4305@teddy.UUCP> <2643@tekgvs.TEK.COM>
Reply-To: agnew@trwrc.UUCP (R.A. Agnew)
Distribution: na
Organization: TRW/MEAD San Diego, Ca.
Lines: 24

In article <2643@tekgvs.TEK.COM> keithe@tekgvs.UUCP (Keith Ericson) writes:
>In article <4305@teddy.UUCP> jpn@teddy.UUCP (John P. Nelson) writes:
>>I'm trying to put together a 80386 UNIX system.  I'd like to hear any
>>recommendations/horror stories that the net might have, both Hardware
>>and Software.
>>
You'll get severely bottlenecked at the disk. Use a 16 bit, high speed 
controller like the Adaptek AT model. I don't remember the model but it
is available in both 2,7 RLL and 2,7 ARRL. If your drive can take it,
use the ARRL as this will double the transfer rate from ST506/412 to
10 Mbits. I have had great luck with the Vertex V170 and 2,7 RLL at
90 Mbytes and 7.5M. I don't know if it will support the bandwidth for
ARRL so ask Adaptek. ARRL would give you 120 Mbytes, 19 ms., 10 Mbits
for less than $1k and the V190 would take you to 140 Mbytes for little more.
You might also consider a SCSI interface which supports 4 Mbytes 
synchronous rates, especially if you plan to use multiple drives
with overlapped seeks and a streaming tape. The 386 can handle it.
The Adaptek controller has a third-party DMA.
	Make sure you format the drive for 1:1 interleave and set the 
transfer size to 26K (RLL) or 34K (ARRL) if you can. Under DOS
use 32K clusters. You should consider implementing a full track 
buffer. These techniques can reduce the time to FSCK the disk
from about 20 minutes to about 15 seconds. The improvement in
multi-user performance is incredible!