Path: utzoo!attcan!uunet!ginosko!gem.mps.ohio-state.edu!rpi!batcomputer!kahn
From: kahn@batcomputer.tn.cornell.edu (Shahin Kahn)
Newsgroups: comp.arch
Subject: Re: ATTACK OF KILLER MICROS
Message-ID: <9119@batcomputer.tn.cornell.edu>
Date: 23 Oct 89 05:26:56 GMT
References: <35825@lll-winken.LLNL.GOV> <2121@brazos.Rice.edu> <35897@lll-winken.LLNL.GOV> <9078@batcomputer.tn.cornell.edu> <36232@lll-winken.LLNL.GOV>
Organization: Theory Center, Cornell U., Ithaca NY
Lines: 41

In article <36232@lll-winken.LLNL.GOV> brooks@maddog.llnl.gov (Eugene Brooks) writes:
>The YMP is 30% faster than a the XMP I was referring to.  This is
>for scalar dominiated compiled code and is a rather general result.
 
If you have scalar dominated code that fits in a workstation's memory
and you dont want to run more than one job at a time, then you are right.
I am sure other users of the YMP will be happy to keep the machine busy
and get good 64-bit megaflops.

>>The single-processor XMP is no-longer a supercomputer.
>Only if the difference between supercomputer and not is a 30% speed increase.
 
I have little desire to defend or promote a YMP, but you cant run a scalar 
code on a vector machine and complain, too!  On the NASA benchamrks, which
I am sure some of this audience has seen, the YMP sustained over 1 GFlops.
THAT, is significantly faster than a single processor XMP.

REWRITE the code!!  Or have someone do it for you (there was a company
that would get your code to run at least twice faster or your money back,
I forget the name and dont know them or anyone who does).  

If they dont perform,
Throw away all the dusty decks.  Refuse to use dusty-deck oriented code.
But if that's all the algorithm can do for now, then yes, use whatever
gives you the desired performance at the least life-time cost (not price!)

>I have no interest in single cpu micros with less than 128MB.
>I prefer 256 MB.  I want enough main memory to hold my problems.

A 256 MB micro can cost you some.  And not so little.  And all that
for just one user.  I am not sure the numbers come out.  And how about IO 
bandwidth and file-size.  maybe your application doesnt need any.  
Talk to a Chemist.
By the time micros become killers, they wont be micros anymore!

>I am talking list price for the system.  A frigging XMP eating micro with

Yes.  My comment about list-price was not directed at Eugene.  Sorry.
I meant to emphasize the importace of using peak-price to go with
peak-performance (I have seen cases where the reported performance is on 
a high-end machine, but the reported price is not!).