Dumb 3dMark06 Question

[Blacklash]

This concerns HD 3850 Crossfire and CPU speed. Below are comparisons of HD 3850 Crossfire. One bench was done with a Q6600 @ 3.5GHz and the other with an Agena 9600 @ 2.5GHz. It's obvious the CPU is limiting the Crossfire setup because the FPS variation is up to 20 FPS in some tests. What baffles me is why "Canyon Flight" only varies by about 4FPS. I see peaks well over 130FPS regardless of the CPU in that test. So I am wondering why it limits HD 3850 Crossfire sharply in the other tests, like the first and last, but has little impact in "Canyon Flight."

 

[Freak'n Big Panda]

I guess I'll just state the obvious and say that canyon flight is more GPU limited than CPU limited. This sorta makes sense given that canyon flight consists mostly of large open scenes with lots of triangles and lighting and whatnot.

 

[BRiT]

Drivers?

 

[Mendel]

It seems HDR1 test (or game test 3, canyon flight) is very pixel shader limited.

Below is a very cpu limited comparison of a GTS640 vs GTS 512 running with atlon 64 x2 4600+

With a professional version of 3dmark I can also run some other tests in 3dmark. Here, the "pixel shader" test is using the shader also used in the cave walls.(though with only vertex lighting)

As you can see, even in heavily cpu limited setup, both the pixel shader test score and the canyon flight score scale very well with additional shading power!