I've noticed that PT only uses 50% of the CPU. I guess if it used 100% then the frame-rates would be double, and loading times would be halved. So what d'you say?
I use a Core 2 Duo and about 50% of each core is being used, in case you needed to know.
The other problem (For someone like me) is that the powder toy doesn't support dual cores, so can only use one. I have it automatically set to use both, but it only ever uses one, which tells my computer it only uses 50%
I have an: AMD Turion(tm) X2 Dual-Core Mobile RM-75 2.20GHz
And since it is dual core, it only uses one For a small increase in speed/ FPS you could try changing the priority of TPT in task manager.