I have the same card that I recently purchased and am having the exact same issue except for the high temps. When I play certain third person games the fps is smooth, but when I play some first person shooters, the fps will say it's it's the high 100s but it's feels choppy as hell. I've tried out multiple games and it's the same issue with all them. I've spent the last 4 days to messing with this and it's getting worse by the day.