Okay I'm currently purchasing this evga gtx 960 2gb for £105 but then I came across this other 960 for £140 for a 4gb model, I looked around online and found out that there isn't much of a performance boost for the 4gb model, but then I thought what if I buy both and sli them, I've done all the checking to see if my motherboard and psu can support this, I just want to know.
.
Are the 2gb 960 and 4gb 960 compatible for sli, are these two cards able to do sli?