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From: dan@rna.UUCP (Dan Ts'o)
Newsgroups: comp.periphs
Subject: Re: VME disk controller review (Cheetah, Rimfire) (long)
Message-ID: <652@rna.UUCP>
Date: Mon, 7-Sep-87 17:20:46 EDT
Article-I.D.: rna.652
Posted: Mon Sep  7 17:20:46 1987
Date-Received: Tue, 8-Sep-87 05:36:04 EDT
References: <8709062258.AA22818@ephemeral.ai.toronto.edu>
Reply-To: dan@rna.UUCP (Dan Ts'o)
Organization: Rockefeller Neurobiology
Lines: 51

In article <8709062258.AA22818@ephemeral.ai.toronto.edu> rayan@utegc.UUCP writes:
>
>With the faster CPUs we've been seeing lately, we have noticed that too
>many processes spend their wall clock time in disk waits. The disk i/o
>subsystem indeed seems to be one of the top 2 bottlenecks (along with
>memory starvation) for our systems. We've been looking for something better
>than our trusty Xylogics 451's, which has been the default controller
>around here until now. To our knowledge, there are three companies in the
>market with high-performance controllers that are/will be used in Suns,
>namely Interphase, Ciprico, and Xylogics. The contending products are:
>
>Interphase:	4200 "Cheetah"
>Ciprico:	3200 "Rimfire"
>Xylogics:	75* Sun default
>
>At this time, I can release my evaluation of two of these boards.
>What follows are my impressions of the products, along with a few numbers
>for people who like to see the mundane stuff.
>
>The boards compared are the Cheetah and the Rimfire. In summary, the
>Cheetah is very fast on flat out reads (at 2MB/sec read, it approaches
>the theoretical limit of 2.4MB/Sec for this disk, especially considering
>sector control data). The Cheetah firmware fell flat on its face when asked
>to do I *and* O interleaved, and degraded to about Xy451 performance levels.
>In comparison, the Rimfire did 1.8MB/sec on a flat out read, but did much
>better on mixed I/O. Based on this gross error in the Cheetah, and the
>results of the benchmarks, I'd give the current overall performance edge to
>the Ciprico board.

	I went through a similar decision cycle for the Sun several months
ago. (For better or worse), we decided on the Xylogics 752. Well, we've had
to wait a long time, something I might not have done, had I known. But we
just did get a 752 with the Sun driver and boot. Actually, the hardware
has been ready for at least 3 months, but they contracted Sun consulting
to do the software, and it has been slow in coming.
	In any case, the installation has been nearly flawless (a very minor
glitch occurred, nothing substantial), and we have ben running for a little
while. I'll try to digest your long posting to see if I can arrive at
comparable stats for the 752. If you have any canned shell scripts or
distilled benchmarks, I'd be happy to run them.
	Anyways, I think the Xylogics (now) is very much a contender in the
VME disk controller race. Certainly Sun decided on them. We almost went with
Interphase, but the promise of continued Sun compatibility persuaded us to
wait (what we thought would be just a short while).

				Cheers,
				Dan Ts'o
				Dept. Neurobiology	212-570-7671
				Rockefeller Univ.	...cmcl2!rna!dan
				1230 York Ave.		rna!dan@nyu.arpa
				NY, NY 10021