Why do I need 2 PCIE slots on my mother board for it to be SLI compatable?

Question

I am looking to buy a GeForce® 7950 GX2 and it says it needs my mother board to be SLI compatable, can someone please explain, and tell me what is the best graphics card I can get for this mother board if not?

http://h10025.www1.hp.com/ewfrf/wc/document?docname=c00300023&lc=en&cc=us&dlc=en&product=1119310&lang=en

Answer 1

Sure, the 7950GX2 would fit in just 1 slot. But that card is actually composed of 2 GPUs and SLI enabled by itself. It may have issues with motherboards that do not support SLI. Ideally the second PCIe slot is for quad SLI mode.

Answer 2

SLI (Scalable Link Interface ) Requires 2 pci-e slots because it actually takes 2 video cards to enable SLI. SLI links the 2 video cards together for better performance. However it does take a bigger power supply and depending on your motherboard there can be a noticeable loss in performance. The older motherboards have 16x pci-e slots but they actually divide the 2 slots into 8x when you are running 2 video cards.Make sure your motherboard supports full 16x on each slot when you are running SLI.As far as video cards I would go with either the 7950 or the 8800 they are both good performers but they are a little pricey so just remember if you want to run SLI you have to buy 2 cards that match.So times the cost by 2. Hope this helped

Answer 3

A 7950 is a good graphics card for SLI. Just remember you need two of the same card with the same amount of video memory. SLI is supported by most motherboards that have 2 PCI-E slots, but check you specs.

If you want the latest and greatest get two 8800GTS or GTX's. With the GTS make sure both have the same amount of memory. There is a 320MB and 640 MB version. You can put a 320 with a 640 but the system will ony access the lower 320 of the 640 mb board. So in effect you are wasting some of the video memory.