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Path: utzoo!utcsri!greg
From: greg@utcsri.UUCP (Gregory Smith)
Newsgroups: net.arch
Subject: Re: Speed is the one true performance metric
Message-ID: <3576@utcsri.UUCP>
Date: Tue, 4-Nov-86 14:35:46 EST
Article-I.D.: utcsri.3576
Posted: Tue Nov  4 14:35:46 1986
Date-Received: Tue, 4-Nov-86 14:43:04 EST
References: <340@euroies.UUCP> <1989@videovax.UUCP> <798@spar.SPAR.SLB.COM>
Reply-To: greg@utcsri.UUCP (Gregory Smith)
Organization: CSRI, University of Toronto
Lines: 31
Summary: 

In article <798@spar.SPAR.SLB.COM> singer@spar.UUCP (David Singer) writes:
>In article <12142@watnot.UUCP> ccplumb@watnot.UUCP (Colin Plumb) writes:
>>In article <1903@mmintl.UUCP> franka@mmintl.UUCP (Frank Adams) writes:
>>>I must disagree.  Reliability is at least as important as speed.
>>
>>I must disagree.  The the idea is to get as much effective speed out of the
>>machine as possible.  A machine that is down 50% of the time delivers 1/2
>>of its operational speed to the user as throughput. Turnaround time (which is
>>what most people are interested in) will suffer more, under most circumstances.
>
>I really fail to see how an immediate or rapid answer you can't trust
>is of any use at all.

This is silly. Broken computers don't give wrong answers. They crash,
or they log soft errors, or they act flaky. It is almost impossible to
imagine a hardware fault that would have no visible effect other than
to make the 'value' (whatever it may be) of the output wrong.

Of course, floating point hardware is a little different, since it
is used only for numerical calculations which are part of the problem
( as opposed to the CPU alu which is also used for indexing, etc.)
You can always arrange to run an FPU diagnostic every 5 mins if this
is an issue.

There are few things more useless than a computer that executes
instructions correctly 999 times out of 1000....

-- 
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Greg Smith     University of Toronto      UUCP: ..utzoo!utcsri!greg
Have vAX, will hack...