Hi, what's the break up of the score?
3DMark Score
SM 2.0 Score
SM 3.0 Score
CPU Score
Graphics Tests
1 - Return to Proxycon
2 - Firefly Forest
CPU Tests
CPU1 - Red Valley
CPU2 - Red Valley
HDR Tests
1 - Canyon Flight (SM 3.0)
2 - Deep Freeze (SM 3.0)
CPU can have a big effect on 3D Mark 06 results, the following is a 8800GTS320 with different CPUs, same hardware (yes, changes in FSB to suit processor):
Cel 347 @ 3GHz 4334 marks, SM 2.0 = 1865, SM 3.0 = 2614, CPU = 761.
P4 631 @ 3GHz 5178 marks, SM 2.0 = 2370, SM 3.0 = 3023, CPU = 895.
E6850 @ 3GHz 9726 marks, SM 2.0 = 3970, SM 3.0 = 4044, CPU = 2614.
Note that Tom's Hardware has SM 2.0 as 4315 and SM 3.0 as 4568 for this card, so this means my GTS ran at the following percentages compared to the 4315/4568 scores due to CPU bottleneck:
Cel 347 SM 2.0 43%, SM 3.0 57%.
P4 631 SM 2.0 55%, SM 3.0 61%.
E6850 SM 2.0 92%, SM 3.0 89%.
So even though they all ran at 3GHz on the same rig with the same hardware, it can just show how CPU clock speed is not everything. To put it another way, 3.4GHz on your Athlon is not the same as 3.4GHz on a Core 2 Duo or Quad.
If you're comparing your score with other Athlon64 X2 @ 3.4GHz + 3870x2 + 2GB RAM + XP systems and you're finding it low, maybe the break up of the 3D Mark score will help explain it.
If you're comparing your score with other systems that are running different CPUs at or around 3.4GHz, then it could well be apples and oranges.
Check your SM 2.0 and 3.0 scores against Tom's first to see how much there is to gain. If they are within 10% of those scores, then CPU may not have much to do with it. More than that it could very well the CPU holding things back (a little or a lot).
I'm getting 14200 marks with 2 x 8800GT512s SLIed, but the CPU score is 2676. It's the same CPU as above with the GTS320 that scored 2614. Only 62 CPU points more, but over 4470 3D marks more.
While not Athlon/3870x2, hope this helps anyway.