Try setting this in your conf.ini:
ProcessAffinityMask=2
This tells windows to run IL-2 only on core 1. For AMD dual core processors, this can make a considerable difference. I run an ancient 939 4200+ X2 @ 2.64G; if I don't use this setting my display occasionally freezes for a second or so (usually upon encountering a combat situation
), and if something explodes, the FPS goes to down to about 3 for a second or so. Good Luck!