Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!dimacs.rutgers.edu!mips!cs.uoregon.edu!ogicse!borasky
From: borasky@ogicse.ogi.edu (M. Edward Borasky)
Newsgroups: comp.benchmarks
Subject: Re: bc benchmark [sigh]
Message-ID: <15424@ogicse.ogi.edu>
Date: 28 Dec 90 15:27:41 GMT
References: <44342@mips.mips.COM> <15379@ogicse.ogi.edu> <1142@telesoft.com>
Organization: Oregon Graduate Institute (formerly OGC), Beaverton, OR
Lines: 55

In article <1142@telesoft.com> choll@telesoft.com (Chris Holl @adonna) writes:
>When I worked at Boeing Computer Services we typically looked for one
>number to compare two machines.  
[...]
>  This was needed because as a computer service, there had to be
>a way to consistently charge customers independent of which box their
>job actually ran on.  
[...]
>In fact, we had to guarantee this for our government customers who
>insisted that their bill for the same job should always be within some
>percentage (5%, I think).
I was hoping for a response like this.  There are two types of computer
users -- those like you and me who realize that computing costs money,
is a resource that must and can be managed, and those like students,
computer science faculty, dreamer/architects who think that computing
should be, can be and often is essentially free.  Granted, you can pick
YOUR favorite speed number (let's say SPECmarks) and come up with a
very low cost box that sits on your desk and delivers it, complete
with stunning 3D graphics and UNIX and some kind of windowing.  But
although the user of this box may think of $10K as very little money,
the company or university who bought 100 of them (now we're talking a
million) PLUS the Ethernet PLUS the guy who comes and bails you out
when you delete your whole directory accidentally plus the guy who
backs your files up once a week so you CAN get bailed out, etc. -- the
company/university has a large investment here.
>
>For example, we compared a Cray 1 to a Cray X-MP.  The clocks were
>12.5 to 9.5 nanoseconds.  All the ratios looked fine (1.32 give or
>take a bit) except scatter/gather which was 10 to 14 times faster on
>the X!  (Hardware scatter/gather - architecture change.)  A job that
>performed a lot of scatter/gather would burn different amounts of CPU
>seconds on the different Crays.
I'll bet that the COST difference between the two machines was such
that you could afford to give away the extra speed on th X-MP from
the hardware scatter/gather -- bill the X-MP as if it were strictly
1.32 times the Cray 1.
>
>The other "one number" we used was for capacity planning.  After
You just said the secret word -- "capacity planning"!  I wish the duck
were still around to drop down and give you fifty dollars!
>(Dr. Howard "Doc" Schemising - wonderful guy) developed a capacity 
>test that would precisely model the current workload on a machine.
>This was used with great accuracy to measure the capacity of different
>machine (for that workload).
Is this published?  Could you post it?  The guys here and in "comp.arch"
would LOVE to see it!
>
[...]
>Unfortunately that is not what
>most people are looking for.  They want you to tell them how fast
>their jobs are going to be on machine X if they are this fast on Y.
Yes, for that you DO need more than ONE number.  But for supercomputers
and supercomputer applications, you can do a damn fine job with THREE
numbers!  Two numbers to describe the computer and one for the appli-
cation.