Whazzat? GeForce 7800 clocks questioned
The folks at Guru3D have found some interesting things about the GeForce 7800 GTX's behavior when 3D apps are running:
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 (see image below).
Read the rest to see what they've found so far. They have a preliminary answer from NVIDIA about this issue, but the fog only thickens as NVIDIA talks about "more complex clocking inside the chip" and a "primary clock speed." Folks are now speculating about the possibility of different clock speeds for different parts of the graphics pipeline. Interesting.