Right now, we don't have thread affinity, so any such information
would be immediately stale. That is, even if you were able to get
your threads started off on all the right processors they wouldn't
stay there. You can actually see this on a MP machine with a single
threaded app, using the Activity Monitor. It will migrate back and
forth among the processors over time.
To be honest, I thought this was intentional to keep both processors
more or less at the same load level and thus temperature, allowing
for less fan activity. If this would be fixed in the future, I think
it would be a good idea to disable it at least in "Reduced"
performance mode (and possibly also automatic as long as the load is
below "75% * ncpu" or so).
