Same thing happend to me , with my old AMD card VLM tracks had better performance than the ISI tracks , now ive upgraded to NVID and see FPS in the 125 range for the others and 60's with the VLM tracks , its a stable 60 and i can add 20+ cars and it only goes down a little however it never reaches into the 100+ fps i now get on 90% of the rf2 tracks ..