AsRock Z77Pro3 not support sli, but Z77 Extreme4-M yes and i have find it for €93,41
It's cheap price and i can try without waste much money If I have to buy another GPU.
@Quaker.... ty for your patience!
but my answer is for the option between my 2 geforce or 1 new GPU .
example:
1°build
cpu i5-3570k €219,99
mb Gigabyte GA-Z77X-D3H €131,99
gpu 2xgeforce8800gt-512 € 0
ram Corsair XMS3(2x4GB) € 45,29
Ty for reply
Maybe I expressed myself badly . I have "2x geforce8800" and I try to understand if it is worth use this 2 card or buy one new GPU.This SLi configuration (performance), is similar to which good current 1xGPU? It's worth the extra money ?
I don't want any great claims only to be able to see what happens in WvW in real time !!!!!