Multimedia Instructions Score vs Video Card

[Billd27023]

I've got a Dell XPS 650. Have an NVIDIA 8800GT which died. Used an 8500GT while I waited for a GTS 450 to show up in the mail. Have Performance tests from all three from within the last month. The 8800 and 8500 give Multimedia Instructions scores of 11.4 and 11.1 respectively but the 450 drops to 8.4. That's a 36% difference. Everything else on the CPU test is within a few percent for all three.

Any thoughts or suggestions why the difference and is there anything I can do about it? Or even if it's an important difference?

[Michael (Passmark)]

The CPU Multimedia test makes use of SIMD instructions (http://en.wikipedia.org/wiki/SIMD). These should not be at all affected by the graphics card installed in the system.

Most likely this is some sort of coincidence unrelated to the video card switch.