I'm unsure how the architecture is deployed and how OS/X handles the
physical cores, but it almost sounds like one Physical core is being
used
(Using Hyperthreads to run 2 threads simultaneously). I wonder if
the memory
is shared across all the cores? A friend of mine was suggesting that
people
may have to wait for Snow Lapard to come out before OS/X properly
utilizes
the Nehalem architecture (whetehr that si true or not, I don't know).
Anyway, as an experiment. If you run 2 copies of Gnubg at the same
time
(using multiple threads) do you get 400% CPU usage?