Under SLI requirements står der følgende: - All GPUs must have the same amount of VRAM and an identical Bus Width -- You cannot use a "256MB" version with a "512MB" version or "1GB" version with a "2GB" version in SLI or a 1GB 192 bit bus with a 1GB 256 bit bus Etc. Note: It used to be possible to enable SLI on cards with differing VRAM (EG 8800GTS 640 and 320) via the "coolbits" mod. However, this mod will not work with newer cards or newer drivers.