I suppose I'll likely find out soon, but was just curious to get some initial idea, how accurate is that number. If it says I will get 1B threads/sec, can I expect that number? 1/2? 1/4? I don't trust the number on some architectures since on the older ones, it says I'd use 2 GP registers, and see 3-4x performance vs a cayman. I kind-of find that hard to believe. I am targetting more modern GPU's, and perhaps using instructions not present on them, do they just get "optmized out" on the older architectures showing me huge performace numbers?