The problem with the GUI miner is that I am getting only about 50-80% usage on my 5870, guessing this is either due to the fact that I am folding on all my cores (F@H) or the miner itself.
Wait, so you think you might be folding on the 5870 as well as mining?
No, -bigadv on my CPU, my 5870 has been idle. But if the miner uses any CPU at all, wouldn't that slow it down due to the fact that my CPU is at 100% (due to folding)