I don't know where you heard that but it is not true. The GTX 560 is based on the GF114 processor which is a respin of the GF104 gpu originally in the GTX 460 with all of it's cores unlocked. The GTX 470/480/465 where all based on the GF100 processor which was later respun into the GF110(GTX 570/580.) Different processors cannot be used together in a dual card setup. For SLI specifically you need the exact same card. You can't even SLI a GTX 460 1gb with a GTX 460 768mb. The only exception to this is cards that Nvidia simply changed the name of while keeping the exact same processor(ie the 9800GTX & GTS 250.) For ATI cards you CAN crossfire as long as they are based on the same processor.