Dorado bytecodes per second

Jecel Assumpcao Jr jecel at merlintec.com
Thu Apr 28 00:48:50 UTC 2005


I am trying to get a feel for how different hardware options perform
running Squeak and how that translates in practice into the user's
experience.

We currently use mainly the bytecodes/second and sends/second numbers
for this which aren't available for older machines. I was particularly
interested in the Dorado since that was considered the minimum
performance for "acceptable" Smalltalking and other machines were
evaluated in terms of how many Dorados they got (normally a small
percentage in the early days).

By running the benchmarks for the "green book" and doing a lot of rough
extrapolations, my guess is that the Dorado would get between 200K and
400K bytecodes/sec. That is better than what I got running Squeak 1.16
on a 33MHz 486 machine which was some 13 years newer, but far below what
I expected. My impression was that the old 20MHz ECL computer was able
to reach a peak of one bytecode per clock
which would indicate a number around three or four times better.

After looking at a bunch of numbers my conclusion is that Squeak is
usable on machines capable of at least 20M bps. If my guess above is
corrent, that would be around 60 Dorados. If both estimates are true,
then I wonder if our definition of "acceptable" has changed or if Squeak
has become less efficient. Certainly Morphic is always being blamed for
slowing everything down, so the latter is probably the case.

If anyone has actual numbers, I would like to see them.

The Dorado was really, really impressive. If re-implemented on a modern
FPGA (not the low cost ones) it would be at most about six times faster
than the original. That would be too slow for Squeak. As a custom chip
in a slightly older process (0.18um for example) it would be around ten
times faster than that, which would be just "usable". This doesn't make
sense to me. The fastest machines are getting about 200M bps out of the
interpreter and Bryce's compiler improves that to nearly 700M bps. I
think I have lost an order of magnitude somewhere along the way.

-- Jecel



More information about the Squeak-dev mailing list