If you were a kde user, you should also consider 'ksysguard' which does a lot of the 'top' and 'ps' stuff. It takes a bit of configuring to get exactly what you want out of it (and does use a slightly worrying level of the performance of your system), but it can do it.
How do I really put this baby through its paces?
I mean, how do I use one process for one processor vs the other, etc?
Note that none of these answers, either yours or mine, seem to answer the question that you asked: these are all monitoring apps, rather than ways of putting a certain load on the processors, nor are they ways of setting the processor affinity (which would probably be a bad idea in this case, anyway).