Date: Wed, 16 Oct 91 09:50:48 -0700
To: Mike Barnes
From: David D. Levine
Subject: Re: TeraFLOPs contest...
========
THE TERAFLOP THROUGH HISTORY
Using a pocket calculator, you can perform about one floating-point
operation every second. At that rate, it would take you about 31,710
years to perform a TeraFLOP.
But the entire history of the human race is shorter than that. Let's
give the human beings a head-start on the computers... we'll start at
the time of King Tut, about 3300 years ago. Of course, they didn't
have calculators back then, so we'll assume that the Egyptian scribes
could perform one floating-point operation every *ten* seconds. At
that rate it would require 317,098 scribe-years to perform a TeraFLOP.
So if a team of 100 scribes began scribbling away at the time of King
Tut, and did nothing but floating-point math 24 hours a day, 365 days a
year, never resting, never dying, they'd just be finishing up a
TeraFLOP today.
It scarcely seems fair, to keep all those scribes busy for so long on
such a boring job. What would it take to perform a TeraFLOP in one
working lifetime -- say, 50 years of 40-hour weeks? 50 years ago, in
1941, the best available calculating device was an electric adding
machine. Suppose an accountant using one of these machines could
perform a floating-point operation in about three seconds. That's
48,000 operations in a 40-hour work week; 2,400,000 operations in a
50-week working year. At that rate it would take about 416,667
accountant-years to perform a TeraFLOP. So if a team of 8333
accountants began churning away in 1941 and did nothing but
floating-point math eight hours a day, five days a week, they'd
just be finishing up a TeraFLOP today.
8333 accountants is all the accountants in a large city, or the entire
population of a small town! We can't tie up all those accountants for
50 years... most of them would have been needed for the War Effort
during WWII. OK, let's get really serious about it. We'll put the
entire population of the United States of America -- 200 million people
-- to work on this TeraFLOP. If we divide it up evenly, each of us has
to do "only" 5000 calculations. If you sat down with your pocket
calculator, at about one floating-point operation per second, you could
finish your part of the job in a little over 83 minutes.* If you
divided it out over a year, you'd have to do 14 calculations per
day... which, unless you have a scientific or financial job, is
probably pretty close to the number of calculations you actually do in
an average day. That implies that the total number of calculations
that the entire population of "average Americans" does in a year is
close to a TeraFLOP.
* The thought of the entire population of the United States punching
away at calculators for an hour and a half brings to mind April 15. In
fact, though, when you do your taxes you spend only a tiny fraction of
the time actually performing calculation. There are less than 100
calculations involved in the preparation of Form 1040. If half the
people in the United States -- 100 million people -- fill out a tax
form each year, that's only 1/100 of a TeraFLOP. So another way of
looking at a TeraFLOP is that it's all the calculations in a hundred
years of Form 1040's. Since the income tax is only about 60 years old,
that implies that the total number of calculations in all the tax forms
ever filed in the United States is close to a TeraFLOP.
- David Levine