In Far Cry 2, when I set it to "Optimal" in the display settings, everything goes to the lowest setting. At that setting the fps wavers between 72 - 128, and when I use the "Very High" setting I get between 20 and 47 FPS. I have AA at 2x. The resolution doesn't seem to make a difference: it's the same at 1920 * 1080 as it is at 1440 * 900.
In Assassin's Creed, at 1920 * 1080, 1/3 Multisampling and 4/4 graphic quality I get between 38 and 53 FPS.
Aren't these frame rates low for the system? What could be causing it?
I have already installed the latest Nvidia drivers.
That looks like your cpu is getting a bit hot to be honest, and to deal with it
Thermal protection is kicking in, reducing the clock speed of your cpu.
That can be the cause of low Fps in games.
Do temp test of your cpu while playing the games you talk about.
If you do find the temps are high, ditch the intel stock cooler and splash out
on a good after market one if not already.