[Shootout-list] Yes! Re: Dual CPU machine?

[John Skaller]

On Fri, 2005-05-20 at 00:14 +0200, Shae Matijs Erisson wrote:
> Greg Buchholz <sleepingsquirrel@yahoo.com> writes:

> My desktop is a two cpu 1544MHz Athlon MP, so I'm very interested.

So am I .. do you have ANY simplish C programs that benefit
significantly?

> With the sudden upsurge of multi-core CPUs, I think lots of people will soon be
> interested in this.  Can multiple CPUs can be simulated with User Mode Linux or
> something similar?

Semantically perhaps, but there is no way to 'simulate' a performance
measurement based on a real time clock, without making the kind
of assumptions which the benchmarks would actually be checking.

Ocaml, for example, can spawn threads, but they cannot 
be concurrent (there is a global lock to protect the garbage
collector which isn't thread-safe).

OTOH many problems can easily be divided between processes
and use message passing -- numerical problems are typical,
where there is a very expensive calculation on a small
amount of data.

> For me, the most interesting benchmark would be "scaling". 
> It would test to see how well a benchmark implementation scales from one cpu up
> to thirty two cpus.

Indeed .. but you'll need a 32 CPU machine to test do the 
measurements  .. the year after next we'll surely have 
4 core CPUs .. :)

-- 
John Skaller, skaller at users.sf.net
PO Box 401 Glebe, NSW 2037, Australia Ph:61-2-96600850 
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