Careful how you judge a cache by its size. A well tuned small cache size
with the speed of the backend can be faster than large cache size with a
lousy backend. I am not saying HP's RAID product is good, only just be
careful of judging on size. For example, if I have 1 GB cache linked to a
50Mhz CPU controlled disc controller and 256 MB cache with a 400Mhz
controlled disc controller. I might be able to beat the first with the
second, given that the 400Mhz should be able to control more disc
mechanisms.

James

P.S. A good cache feeds the system with enough info to keep it from waiting.

-----Original Message-----
From: HP-3000 Systems Discussion [mailto:[log in to unmask]]On
Behalf Of John Clogg
Sent: Friday, December 10, 1999 12:12 PM
To: [log in to unmask]
Subject: Re: RAID5 Disc's


Good points. However, I have heard disk array sales people try to claim
controller caching improves both read and write performance.  In answer to
your question in your other posting, the AutoRAID cache is 96 MB, pretty
small by today's standards.

-----Original Message-----
From: Steve Dirickson [mailto:[log in to unmask]]
Sent: Thursday, December 09, 1999 8:39 PM
To: [log in to unmask]
Subject: Re: RAID5 Disc's


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