Hey all. I just got a second 3870x2 that I installed on my DFI X38 mobo. With one card installed I got between 13300 and 13400 3DMarks. With the second card my score only went up by about 500 points.

Is there any way I can make sure both cards are working? I ran the Shader Mark test with both cards in and got around 1275 fps. Under "Details" in 3DM06 under "System" I saw this:

DirectDraw
Version 6.0.6000.16386 Primary Device ATI Radeon HD 3870 X2 Linked Display Adapters false
Unfortunately, I never noticed if it was on for one cards, but IIRC it was on for dual 2900XT's.

System info:
Q6600
DFI X38-T2R
4 x 1GB G.Skil PC_4200 HZ's
Two 3870x2's
4 x 250 GB Seagate 7200.11's
Thermaltake ToughPower 850W
Vista Business SP1