Path: utzoo!mnetor!uunet!husc6!mit-eddie!ll-xn!ames!pacbell!att-ih!ihnp4!inuxc!iuvax!pur-ee!uiucdcs!uxc.cso.uiuc.edu!clio!berger
From: berger@clio.las.uiuc.edu
Newsgroups: comp.sys.ibm.pc
Subject: Re: ESDI vs SCSI vs MFM
Message-ID: <16800229@clio>
Date: 14 Mar 88 22:42:00 GMT
References: <4302@b-tech.UUCP>
Lines: 22
Nf-ID: #R:b-tech.UUCP:4302:clio:16800229:000:859
Nf-From: clio.las.uiuc.edu!berger    Mar 14 16:42:00 1988


According to the official SCSI document from the standards committee,
the SCSI bandwidth is about 1.5 megaBYTES/second.  ESDI is somewhat
faster.  Some implementations of SCSI have been discussed that run
at twice the nominal speed, but I'm not sure there are any in
operation.

The actual throughput from a SCSI device also depends on how you've
implemented the protocol.  Most off-the-shelf SCSI devices seem to
hold the bus and wait until your request can be served, although
the specification allows the device to release the bus and request
it again when ready.  This will certainly slow things down.

In any case, your original figures are in conflict with my data.

			Mike Berger
			Department of Statistics 
			Science, Technology, and Society
			University of Illinois 

			berger@clio.las.uiuc.edu
			{ihnp4 | convex | pur-ee}!uiucuxc!clio!berger