I have 3 pci-express slots. Two are blue, indicating that they function at the full x16 speed/lanes; the third is white because it only functions at x4 speed. I have one gtx 470 in the first, full speed slot, and i'm trying to figure out where to put the second 470. If i put it in the second full speed slot, it is so close to the first card that it increases my temps, so i thought i'd move the second card to the next pci-express slot down, which would give me more space between cards and decrease my temps; BUT doing this would put the second card in a pci-express slot that only supports x4 lanes instead of x16....
So my "real" question is; would moving the card to the slower PCI-express slot limit the graphics card in any way, maybe by causing a bottleneck or something?
And in answer to your first question "Is the question not "can I run just one GTX470"? I run a P6T Deluxe, and the only reason I run two cards is the three 23" freaking screens. You've got one...so what's the real issue?
I want to run both cards because for one, i have two cards so why wouldn't i use the second one, and two, my monitor is a 27" monitor at 1920x1200 resolution and with games like Mafia 2, one card struggles a bit with physX on.
I've also checked the GPU usage while playing the game and it's at 100 percent most of the time, so it's not a cpu bottleneck that causes trouble playing the game...it's just that at that high of resolution with all settings maxed and the PhysX turned on, one GTX 470 isn't quite enough for a smooth gameplay experience.
Here is a link the shows a picture of my MB. On the left hand side you can see two blue PCIe slots and one white one...these are the ones i'm talking about, in case my descriptions weren't accurate enough.http://www.techwarelabs.com/asus-p6t/
And why couldn't I run 3 graphics cards?...MaxPC does it all the time, or at least reviews pc's that do. I have 3 slots, so why wouldn't i be able to do it?
i7-930 2.8Ghz OC'd to 3.3Ghz
6GB tri-channel DDR3 Corsair Dominator
Asus P6T MB
NZXT Tempest Evo
EVGA GTX 470
1000W Silent Pro