SEUSITES

I am planning on getting a new graphics card for my computer, but I am not sure if the graphics card will fit. I am planning on getting a Geforce 9400. The computer model is a Gateway 838GM. My current graphics card is a intel(R) 82915G/GV/910GL express chipset family. Any help is appreciated.

I think this is called SLI… Although i am looking at graphics cards and it doesnt say anywhere if they are sli compatible.
Am i correct in saying Sli is where you can use 2 graphics cards in 2 pci slots and it adds both graphics memorys up to make a total?

Can people give me advice/info on using 2 graphics cards at once please, im confused?

Cheers!