is this for real? you have a perfect system. if 1080ti didnt work with that, what would it work wit? if you mean because you only have 650 watts, that's pushing it but nvidia recommends 600 watts minimum so you should be good. but if you get a 1080ti with 2 8-pin power plugs instead of a 8-pin plus 6-pin, and overclock it to the balls, you may be full load or more. those things (like zotac amp extreme ) will push 320-350 watts, not 250-300 like founder's edition.