From: Kragen Sitaker (kragen@pobox.com)
Date: Wed Sep 06 2000 - 16:29:02 PDT
Adam forced me to forward this to FoRK at the point of a very sharp pikachu horn.
--
<kragen@pobox.com> Kragen Sitaker <http://www.pobox.com/~kragen/>
Perilous to all of us are the devices of an art deeper than we ourselves
possess.
-- Gandalf the Grey [J.R.R. Tolkien, "Lord of the Rings"]
---------- Forwarded message ----------
Date: Mon, 28 Aug 2000 03:15:41 -0400 (EDT)
From: Kragen <kragen@kirk.dnaco.net>
To: kragen-tol@kragen.dnaco.net
Subject: computing budgeting
Suppose we want to charge fairly for disk usage. You can get a 75GB
disk now for $600; if you have six of these in two RAID-4's mirrored at
different sites to provide 150GB of highly-reliable storage, it will
cost you $3600. If we assume a nominal ROI of 3%, that means it costs
you $108 per year. Irrelevantly tiny.
Disks seem to halve in price in about a year; if we use that as a
seat-of-the-pants basis for depreciation, this setup depreciates $1800
per year, or about $150 per month. (If we assume it's really
exponential, it's about $202 for the first month, but $1 per gigabyte
is a nice round number.)
$1 per month per gigabyte isn't too bad. It works out to about
2 628 000 000 000 000 = 2.6e15 byte-seconds per dollar. Or 3e10
byte-days per dollar. Or 82 million byte-years per dollar.
How about memory? You can buy half an ECC PC133 gigabyte for $850
without any trouble, and it seems you can get it for as little as
$550. (Specialized RAM --- HP NetServer or Compaq Proliant --- costs
much more.) If we go with the $850 figure, and depreciate the same way
as for the disks, we get about $100 per month per gigabyte of RAM.
2.6e13 byte-seconds per dollar.
CPU cycles? You can buy a motherboard with a 750MHz AMD K7 "Athlon"
for a bit under $300. Assume the case is irrelevant to cost (it's
cheap and doesn't depreciate very fast) and that the CPU and mobo
depreciate exponentially, losing half their value within a year, just
like everything else. Then you're spending $17 per month for this
guy. It goes through 1 971 000 000 000 000 --- roughly 2e15 --- clock
cycles in a month. That's 1.1e14 CPU cycles per dollar.
So the prices are:
2.6e15 byte-seconds of extremely reliable online storage per dollar
2.6e13 byte-seconds of high-quality RAM storage per dollar
1.1e14 CPU cycles per dollar
All of this is assuming that no system administration or transaction
cost is needed, of course --- sysadmin costs typically double the real
costs of computer systems, but depend heavily on the usage.
This is very promising. This means that, in an ideal market, if you
can spend a penny per year on your share of shared computing resources,
you could get today:
- 824 454 bytes of disk space, or
- 8 245 bytes of RAM (averaged), or
- 34 880 CPU cycles per second (averaged)
What this says to me is that the traditional stuff timesharing setups
used to charge people for is now all irrelevantly cheap for ordinary
use. What costs money now is other stuff: face time with people, work
in keeping the system running, time spent tracking down intruders and
hitting them with baseball bats, rack space, and bandwidth. And
hardware to interface with people.
If I were building a timesharing system today, I would expect that the
majority of users would spend less than a dollar per year each for disk
space, RAM, and CPU time. I'd still charge them, but I wouldn't bother
to try to extract payment until the balance was over $10.
--
<kragen@pobox.com> Kragen Sitaker <http://www.pobox.com/~kragen/>
Perilous to all of us are the devices of an art deeper than we ourselves
possess.
-- Gandalf the Grey [J.R.R. Tolkien, "Lord of the Rings"]
This archive was generated by hypermail 2b29 : Wed Sep 06 2000 - 16:30:50 PDT