I'd personally go with the 3700. The 3700 is more overclockable, as far as I know. I've got mine to a stable 2.8 GHz without even upping the vcore. I can hit 3.1 GHz if I really try, and with better RAM, I could probably push it to around 3.3-3.4ish. The 3700 is better than the 146, but I think the 148 is a little better than the 3700. If you're going for an Opty, don't settle for less than the 148. It's basically the same as a 3700, but slightly more OCable.