Path: utzoo!attcan!uunet!portal!cup.portal.com!ts
From: ts@cup.portal.com (Tim W Smith)
Newsgroups: comp.sys.mac
Subject: Re: Comparing performance of Quantum and Imprimis hard disks
Message-ID: <22871@cup.portal.com>
Date: 8 Oct 89 02:53:00 GMT
References: <9009@batcomputer.tn.cornell.edu>
Organization: The Portal System (TM)
Lines: 19

Speaking of disk performance, I've noticed that sometimes the manufacturer
will underrate a drive.  For instance, I've got a Quantum ProDrive 80.
According to the manual, this is capable of "Data transfer rate of up to
2.0 asynchronous/4.0 synchronous megabytes/second".

I've also got many things with NCR 53C90 SCSI chips on them.  I recently
had occasion to watch on a 'scope as a 5390, which is rated at something
like 2.5 or 3 meg/sec asynchronous, exchange data with my ProDrive.  I
was using asynchronous mode, so I should have been limited to 2.0 meg/sec.

The data was being exchanged at 4 megabytes/second.  Notice that this is
faster than Quantum says their drive can go, and faster than NCR says
that their chip can go.

Now maybe Quantum has changed their specs, since my manual is marked
as preliminary, but we are still going faster than the 5390 is supposed
to be able to go.

						Tim Smith