Path: utzoo!news-server.csri.toronto.edu!rutgers!cs.utexas.edu!uunet!comp.vuw.ac.nz!actrix!paul
From: paul@actrix.gen.nz (Paul Gillingwater)
Newsgroups: comp.periphs.scsi
Subject: Re: Single-Ended vs Differential
Keywords: SCSI cables
Message-ID: <1991Mar13.000459.23789@actrix.gen.nz>
Date: 13 Mar 91 00:04:59 GMT
References: <3246@legs.UUCP>
Organization: Actrix Information Exchange
Lines: 19
Comment-To: cgn@ast.COM

In article <3246@legs.UUCP> cgn@ast.COM (Chris Nieves) writes:
> I'm hearing a lot of differing views on single-end vs differential
> SCSI cables.  Some say you can do 10MB on SE cable, others say you
> can go 75 feet on SE cable, and some say you can go 10MB AND 75 feet
> on SE cable.  What's the real story here.  Inquiring minds want to
> know!

According to an HP Technical Highlight on SCSI, a single ended SCSI
HBA limits cable lengths to under 6 metres.  Differential SCSI can
handle distances of up to 25 metres.  Obviously, this refers to
what the standard guarantees -- some vendors may wish to extend
these lengths with a sufficient tail wind.  They further claim
that SCSI-2 Fast/Wide can go up to 40 Mb/sec, while SCSI-1 can
handle 10 Mb/s with fast SCSI and up to 20 Mb/s with wide SCSI.

Interestingly, HP also claim that "no major vendors have offered
Fast/Wide SCSI."  Anyone care to contradict that remark?
-- 
Paul Gillingwater, paul@actrix.gen.nz