Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!yale!cmcl2!rutgers!mcdchg!ddsw1!karl
From: karl@ddsw1.MCS.COM (Karl Denninger)
Newsgroups: comp.unix.xenix
Subject: Re: What's new on adaptex
Summary: Do a "dd if=/dev/xxxx of=/dev/null bs=4k count=2000"; what do you get?
Message-ID: <1990Feb5.220150.374@ddsw1.MCS.COM>
Date: 5 Feb 90 22:01:50 GMT
References: <21800001@adaptex> <1458@eutrc3.urc.tue.nl> <25c97303:579.6comp.unix.xenix;1@nstar.UUCP>
Reply-To: karl@mcs.MCS.COM (Karl Denninger)
Organization: Macro Computer Solutions, Inc. - Mundelein, IL
Lines: 26

In article <25c97303:579.6comp.unix.xenix;1@nstar.UUCP> larry@nstar.UUCP (Larry Snyder) writes:
>>So ESDI users should not feel like they missed a great opportunity by not
>>starting off with SCSI. I agree that SCSI may be better from a conceptual

>I agree 100%.  Many times I've seen ESDI subsystems exceed throughput of
>SCSI ones.

And more than a few times I've seen SCSI blow the doors off ESDI.

What's your effective speed (time) reported in the test above with your ESDI
subsystem?  How is it affected by two or more running on >different< drives
on the same controller?  Can you really exceed 1 MB/second through the block
device?  (RAW device information is meaningless; filesystems don't read and
write through them!)

Then add in the fact that you can get a $820 150MB tape backup for SCSI,
versus almost $1300 for the >same< drive in a "board + drive" combination!
Try backing up the system with both combinations -- you'll find the SCSI
device machine is actually usable during the backup -- while the other
system is crawling!

--
Karl Denninger (karl@ddsw1.MCS.COM, <well-connected>!ddsw1!karl)
Public Access Data Line: [+1 708 566-8911], Voice: [+1 708 566-8910]
Macro Computer Solutions, Inc.		"Quality Solutions at a Fair Price"