Can one of you guys do me a favour please... I have a dual core Core 2 Duo overclocked at 3.2Ghz. Game runs ok, but I see frame rate drops to around 30fps or sometimes less.. Can someone with a quad core (preferrably the core 2 quad generation) clocked around 3Ghz, go into the affinity of the .exe and just set it to say core0 and core1 (removing affinity from core2 & core3) and tell me what performance is like compared to having affinity on all 4 cores... ?
I just need to know if its a cpu or gpu limitation I have or maybe a game issue.
I'm running graphics at 1920x1200 , high res textures, af on and motion blur on. Even if i drop resolution to say 1440x900 and take off high res textures, af and motion blur it makes hardly any difference hence i suspect cpu limits.
Thanks,
Right I've just done this

I have a Q6600 at 3.0GHz.
I drove one of the time trial preview races where it was raining and recorded the fps with fraps.
All 4 cores:
Frames, Time (ms), Min, Max, Avg
6045, 102022, 44, 62, 59.252
Just cores 0 and 1 (2 and 3 disabled):
Frames, Time (ms), Min, Max, Avg
6043, 102803, 32, 62, 58.782
Subjectively it didn't seem any different with just two cores, even though the minimum framerate was recorded lower.
If there is a particularly demanding race in the career mode where your framerate slows down badly, tell me which one and I'll try it on my system if you like.