I'm not too familiar with the GF2 Ultra, but I have an Abit Siluro MX440 card and I've clocked it from the default 275/400 core/mem to 315/490. The MX440 is a fine card for its price, and plays today's games well, but will probably not do that well with tomorrow's games(DX8.1 that is). If you have a bit more to spare, go for the GF3 Ti200 or even better, the GF4 Ti4200.