AF is a truly massive program on CPU usage because of the depth, detail, and quality of sounds from a total of 5 internal synth engines. When the minimum cpu usage or demand says 512 MB, that just means to intitialize program. You need 2 gigs to even roll in moderate polyphony. That and your card(even if ASIO) could be just a wheelie bar. GB is decent, but not the best for VSTi . Really good, yet you'd do best with a low graphic, engine full of variables to tweak for optimum performance. Also, if you are working rewire aps, you can kiss responses into delay.