Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!milano!uudell!loft386!dpi
From: dpi@loft386.UUCP (Doug Ingraham)
Newsgroups: comp.unix.xenix
Subject: Re: Perstor Disk Drive Controllers
Keywords: disk drive controllers,experiences requested,how?
Message-ID: <615@loft386.UUCP>
Date: 14 Mar 90 18:21:57 GMT
References: <868@edstip.EDS.COM> <24@psmsd.UUCP>
Distribution: na
Organization: Lofty Pursuits, Rapid City, SD USA
Lines: 53

In article <24@psmsd.UUCP>, pmartin@psmsd.UUCP (Paul Martin) writes:
> In article <868@edstip.EDS.COM>, ohrnb@edstip.EDS.COM (Erik Ohrnberger) writes:
> > 
> > Does anyone have any experience with a Perstore disk controller
> > cards?
> > 
> 
> The perstor will cause your drive to get hotter than normal thus causing
> a failure.  This is because the drive spins faster under the perstor.

Nonsense!  There is no command that can be given to a drive by the controller
that will cause it to spin faster.

> I ran into this problem after having my drive fail.  I moved it to an
> external case and it has work flawlessly ever since.  My mini tower case
> has a poor design for allowing good circulation of cool air.  I also
> have a full complement of boards and memory.

The poor circulation and overloaded ventilation system was probably the
actual cause of failure.

> Also be aware that the controller is not an MFM or an RLL so programs
> like the new spinrite II don't like it.  This is the only package that
> I know of that doesn't like the perstor.  You can even low level format
> with disk manager when using a perstor.  I am running both Xenix/386
> and dos 3.3 with no problems at all.

Speedstore doesn't much like it either.  We tried it on lots of different
drives and decided that though it worked, it worked poorly.  The slow
performance was probably due to the ecc being overworked.  Perstore claims
a proprietary encoding system that doesn't exceed the manufacturers
specifications.
 
> > 7-15 Mb/sec.  How does Perstor achieve 9 MB/sec?  and how reliable are
 
The 1 sector burst rate is 9mb/sec just as its 7.5 mb/sec for RLL and 5mb/sec
on MFM.  There would have to be a track buffer on the controller that could
hold a whole track of data to allow 1-1 interleave.

We were never certain that the controller we had was working properly.  We
found that the data retention would vary with temperature a lot worse than
with MFM.  The other thing we had trouble with was the quality of the
software provided by perstore for formatting and such.  This stuff was clearly
pre-release stuff that I wouldn't have let off my computer or even shown to
anyone if I had written it.  Maybe they have improved the product, but I would
get one of these only with a no questions asked return policy.



-- 
Doug Ingraham (SysAdmin)
Lofty Pursuits (Public Access for Rapid City SD USA)
uunet!loft386!dpi