As you can see from these benchmarks, at 3.0GHz, using both dual and quad cores, the 6MB cache in the Penryn is good for a 9% performance gain in FSX. I suppose this gain would scale with clockspeed. Going from 2 to 4 cores makes no difference in framerate in this test, which uses FSX-SP1.http://sio.midco.net/FTP4/IMG0021312.gifhttp://www.behardware.com/articles/691-7/i...eme-qx9650.html

10% gain and add to that the 20% additional overclock potential, and its a nice gain for FSX, that needs all the gains you can find!