ya it will bottleneck... Mine is p4 2.8c ht and also i have 6600gt. My 3dMark2003 score is only 7755 at 60 hertz and 7650 something at 75 hertz... Other 6600gt with 500/900 frequencies bench about 8K running on AMD system with lower frequencies, about 2.2, 2.4 gig... I really think that P4 sucks on 3d Games. Now i know, the next time i would buy a pc i will go for AMD 64 platform.