Thanks for the reply's.
So would a PNY 9600GT card work with the XFX9600GT? Or do they need to be the same manufacturer?
Also would that even be worth while using a PNY card if it did work?
Yes, different brands will SLi, but try and get the RAM types the same (I don't know if there is a GDDR3 9600GT) GDDR2 with GDDR2 and such because some people have reported Sli not working if the types are not the same.
ill alwais recommand SLIing IDENTICAL cards for the best compatibility.
But a X 9800GT can work with a Y 9800GT. with newer driver the clock of the card dont seems to mater but the memory can still be an issue. Try to at least get a same memory model card. ( IE: 512 with 512 )