Windows multi-threading performance issues on multi-core systems only

[dsimcha]

== Quote from Simen kjaeraas (simen.kjaras at gmail.com)'s article
> dsimcha <dsimcha at yahoo.com> wrote:
> > This is a synthetic, extreme corner case benchmark, but I think it
> > hammers home
> > the point that such problems are at least plausible.  Tested on a Core 2
> > Quad with
> > -O -inline -release:
> > Timing with affinity for all 4 CPUs:  28390 milliseconds
> >
> > Timing with affinity for only 1 CPU:  533 milliseconds
> Tested this on a Core 2 Duo, same options. OS is Windows 7, 64bit. It
> scales roughly inverse linearly with number of threads:
> 163ms for 1,
> 364ms for 2,
> 886ms for 4
> This is quite different from your numbers, though.

Yea, forgot to mention my numbers were on Win XP.  Maybe Windows 7 critical
sections are better implemented or something.   Can a few other people with a
variety of OS's run this benchmark and post their numbers?