if you want to mine using the cpu as well to get a little extra, I've used pooler's miner on q6600 cpu's (old quad core) with 4 threads each getting ~7Kh/s (~28Kh/s total).
not bad for the cpu which would otherwise be sitting there idle.
Well, overall it is not likely worth it, because the CPU consumes more electricity when hashing and that electricity costs more than you earn with coins.