Article View: comp.sys.super
Article #110Re: I/O subsystems (was Re: Supercomputer ROI)
From: yamo Michael Yamasaki
Date: Wed, 30 May 1990 16:26
Date: Wed, 30 May 1990 16:26
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In article <6543@vax1.acs.udel.EDU> mccalpin@vax1.udel.edu (John D Mccalpin) writes:
>
>Well, I guess I am a bit confused, because 10% of the I/O performance of
>a Cray 2 means that your workstation is relatively imbalanced *toward* I/O
>performance, rather than away from it!
>
>My Personal Iris runs my 64-bit codes at about 1-2 MFLOPS, which makes it
>about 1% of a Y/MP. The I/O numbers that I have seen are on the order of
>1 MB/s, while the Cray numbers are on the order of 10 MB/s to disk -- so I
>get about 10% of the Y/MP.
>Thus my machine is 10 times more cost-effective for I/O than for
>computations! (relative to a Y/MP).
>
I didn't intend to say that the Cray's were well balanced flops to I/O.
Some people like to think Crays turn compute bound problems into
I/O bound problems. Uh, I shudder to think what using an Iris with
10% of it's current I/O bandwidth would be like.
(Cost effective? If it takes me the same time to do 10% of a problem, it
wouldn't seem to be cost effective to me. ;-)
The Cray numbers, by the way, are what a typical user might expect for a
single processor job with 50 or so other users. The Iris numbers are of
course for a single user.
-Yamo-
yamo@wk46.nas.nasa.gov
yamo@amelia.nas.nasa.gov
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Path: arc1-ca.pugleaf.net!utzoo!attcan!uunet!aplcen!samsung!rex!ames!amelia!wk46!yamo From: yamo@wk46..nas.nasa.gov (Michael Yamasaki) Newsgroups: comp.sys.super Subject: Re: I/O subsystems (was Re: Supercomputer ROI) Message-ID: <6390@amelia.nas.nasa.gov> Date: 30 May 90 16:26:31 GMT References: <359@garth.UUCP> <6374@amelia.nas.nasa.gov> <6543@vax1.acs.udel.EDU> Sender: news@amelia.nas.nasa.gov Reply-To: yamo@wk46.nas.nasa.gov (Michael Yamasaki) Organization: NASA Ames Research Center Lines: 31