Question: do gpus need to be the same for sli?
Answer: In SLI, you need two cards that have the same GPU—for example, two GTX 560 Tis. They don't have to be from the same manufacturer, they just have to both be GTX 560 Tis. ... Once you install both cards and the necessary bridge, you can open up your driver's control panel and enable SLI or Crossfire.