1080 is the best you can put in there right now as I write this. There may be faster in the next few days though. Also, this isn't to say what's the fastest your processor won't bottleneck too badly, or what's the best at your monitors resolution or what's the best in this price range. You can put almost any modern GPU onto that board. PCIe 2.0 X16 is the slot it would go into, we're on 3.0 right now, but 3.0 cards are backwards compatible with 2.0 and 1.0. Hope this helps.