I was discussing something with Unwinder today (Rivatuner programmer) as he has had a lot of reports of unusual core clocks for the GeForce 7800 GTX. After investigating it myself it seems that the minute you startup a 3D application, the GPU core frequency jumps towards 468 MHz (should be 430), a ~40 MHz difference is reported with any GeForce 7800 GTX. You can only measure this once you actually follow the clock real-time.

I just verified it, during some new test sessions with core clock monitoring we noticed that the G70 although clocked at 430 standard will in 3D applications immediately jump towards 468 MHz. Even overclocked at 480 Mhz the clock will jump towards 522 MHz, again that ~40 MHz difference. What is going on in that G70 GPU huh ??

Guru3D