*BSD News Article 75313


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From: fcawth@jjarray.umd.edu (Fred Cawthorne)
Newsgroups: comp.unix.bsd.freebsd.misc
Subject: Re: Do the 'zip accelerator' cards work as scsi adaptors?
Date: 2 Aug 1996 20:17:31 GMT
Organization: University of Maryland, College Park
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Jeremy Nelson (nelson@cs.uwp.edu) wrote:
: However, i have been abysmally disappointed with its performance.  You
: comment that in your own experience, youre getting 6 megs per minute.
: What strikes me as slightly odd is that even under dos, im getting 4.6 
: megs per minute throughput.  When you compare that to the parallel
: version, which gets 4.5 megs per minute on a generic "el cheapo" parallel
: port, i begin to wonder why the scsi version is not marginally faster.

: To put into numbers what i mean, here are some simple tests i ran:

: Test: Copy Ultimate Doom (13.5 megs) from zip drive to conner 1.6 hd.

: HD to HD -- 12 seconds (about 60 megs per minute)
: Zip Parallel to HD -- 2:53 (about 4.5 megs per minute)
: Zip SCSI to HD -- 2:48 (about 4.6 megs per minute)

Hmmm.  I get 800K/sec with iozone writing a 32 meg file.  This is with a 
P-166 with NCR PCI scsi controllers though.  Real-life performance is 
not too much different.  I routinely copy about 30 megs back and forth
from a zip disk and It takes less than one minute.
: Is that accurate?  Its really disappointing to me if thats all that i
: can hope for out of it -- ill probably return it if thats the max.
: As a consumer gripe, it really peeves me that they offer on the box as
: the example of performance "Up to 20 megs per mintue" for parallel,
: and "up to 60 meg per minute" for scsi, when its apparant that neither
: drive is capable of anywhere close to that.
Don't know about the parrallel one, but the scsi zip is pretty fast for 
what it is. (i.e. a floppy drive with good heads and positioning mechanism).

Fred.