Recently I upgraded my computer and installed a crossfire setup.
I had a a spare GPU, a HD 6790, so I installed it in my sons Computer. It is a Core 2 duo E6750 2.66GHZ (about 4 and half years old) with 4 Gig ram and a 500GB HD. It is a MSI P35 motherboard
Since I have done this the games are lagging. By this I mean MW3 jerks to the next position almost. Like it loses a frame or 2. I have tried everything from replacing the Power supply to a name brand which is 500watt. To removing some ram to see if I had some faulty ram.
Is there a chance the CPU is bottlenecked trying to get information to the GPU?
I dont want to upgrade the CPU and MOBO unless I know it is the problem.
...and yeah, the CPU is on the lowly side for two 6870's... I'd say the cards would def. max out that dual core... You can use MSI Afterburner OSD to check the scaling... if the CPU is bottlenecking (which it probably is) you'll see low scaling and high CPU usage (100%).