there are now 4 different gtx 460's and they need to be the same to sli. You have the SE, which has 288 stream processors and 256 bit memory, you would need another se to make sli work. Then you have the nomal 1 gb card with 336 stream proc. and 256 bit memory, the 768mb with 192 bit memory, and the new 460 which has 1 gb, 336 stream proc. , but only 192 bit memory. Make sure you on't buy any of those other cards. Might be hard to find an SE now though.