My GTX 680 not running at full GPU speed in FSX

[SpeedPilot 0]

While playingg FSX with Precision X running in the background, Precision's OSD shows that my GTX 680's GPU is running at 324MHz and GPU usage between 40-50%. Is this because FSX is not a GPU intensive game? My video card is an EVGA GTX 680 4GB and it's GPU base clock is advertised as 1019MHz with a boost clock of 1084MHz. It runs at between 1079-1084 in the Unigine Heaven benchmark. Is my GTX 680 running as it should in FSX or do I have defective card?

[SpeedPilot 0]

Never mind, I figured out the problem. The performance mode setting was set to Adaptive and I had to change it to Maximum Performance in the video driver settings.

[SAAB340 28]

So did you notice any difference when setting Maximum performance? What AA settings do you use?