Does it matter which PCI-E slot I use?

[gazza_new]

I bought a 7900GTX today and plugged it all in. My CPU temps went up 4C idle and my mobo temps jumped 5C. The 7900GTX seems to cut off some of the airflow and also sits directly on my mobo's heatpipe. I have now moved my 7900GTX down to the second PCI-E slot on my mobo.

Does it matter which one you use? Is there any difference?

 

[Hartz]

If your mobo does not have two PCI-E x16 slots then yes lowering it to the PCI-E x 8 slot will harm performance alot.

 

[Arcygenical]

I don't think it'll lower performance very much... At most 2-3% IIRC. I mean, running in SLI reverts both PCIe slots to 8x (unless you have a very high end board that advertises dual 16x lanes).

Just like there is very little difference between AGP 8x and 4x, PCIe 16x and 8x should be the same.

The reason your CPU temps rose is probably a combination if increased heat output into the case. A small elevation in ambient temp can have a huge effect on temperatures. Take it from the source, my room is 4c warmer today than yesterday, and my CPU temps are idling 8c higher .

 

[DeChache]

Shouldnt make a differnece. Try a game or run a benchmark and find out and let me know. I want to move my card down a slot on my board.