I've activated 3 cores, and my primespersec is a measly 6. Friggin' 6!!! My PC is not *that* old. Is the problem that it's an AMD?
Processor AMD Phenom(tm) II X4 955 Processor, 3200 Mhz, 4 Core(s), 4 Logical Processor(s)
It's possible. I found that some software compiled with intel's ICC compiler runs very bad on non-intel chips. Such as the linpack benchmark. It achieved only 7 GFLOPS on an amd chip that generally is as fast as my laptop's processor, which achieves 14 GFLOPS in linpack.
Maybe the same happens with other stuff.
We'll have to wait for the community to get their hands on it, im sure theyre gonna fork it to be the most efficient thing you have ever seen.