Quote Originally Posted by 'zanthor',index.php?page=Thread&postID=179595#post 179595
One issue with dual video cards is if you try to run on the 2nd video card windows reverts to software rendering instead of hardware, huge performance hit. Many deatils about this in the forums here, search around a bit.
Wow, so that's why I got worse performance. I have a 3 slot mother board and am running a GTX 280 and two 9500GTs. I recently picked up a third 22" and had decided to drop down to 3 monitors and not use the two 17" (desk was really crowded already). When I put a monitor on each card, I found that I got worse performance on the GTX 280 than when it was driving two of the 22"s with 5 WoW clients. I eventually switched back to that setup and ended up with better frame rates, but damn if it didn't puzzle me.

You have any links to more info on this? Is it a issue with nVidia drivers, DirectX or just Windows? I run Vista x64 if it matters.

- Souca -