Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!uunet!jwt!john
From: john@jwt.UUCP (John Temples)
Newsgroups: comp.sys.ibm.pc
Subject: Track caching hard disk controllers
Message-ID: <767@jwt.UUCP>
Date: 6 Dec 89 22:49:58 GMT
Reply-To: john@jwt.UUCP (John Temples)
Organization: John W. Temples, III -- Orlando, FL
Lines: 13


I have a WD1006V-MM2 compatible hard disk controller which has track
caching.  Does anyone know how the track caching feature works in
reading and writing?  I installed one of these controllers on my UNIX
system, and the data read rate doubled, yet the write rate went down
about 25%.  This is in a slow 286 system with the drive formatted 3:1
interleave.  I then tried reformatting to 1:1 interleave.  Read
performance was still about double, yet write performance was down to about
50% of its original value.  Does this mean that a track is still read
in in a single disk revolution regardless of the interleave, and that
writes are not cached?
-- 
John W. Temples -- john@jwt.UUCP (uunet!jwt!john)