I have just upgraded from a X1900XT card (or so I thought)
When running it seems slow so I have run 3d mark 01 se on it mainly as it is a quick download

With my X1900 i get @ 28000 marks
With the hd 3870 I get 9000 marks

SO i guess there is a problem
I have tried

drivers that came with the card
version 8.4 & 8.5 catalyst

Full reformat & reinstall of windows

none of the above work

My specs are
185 opteron socket 939
Asus A8R - MVP mobo (crossfire)
2 x 1 gig Geil memory
2 x 250 gb hdd
windows xp sp3
Tagen 550 watt psu

I have made sure the 6 pin cable in connected & working
All fans are working & temps low

The only thing i can now think of is the pci-e slot on this mobo

Could this be it or can you think of anything else?