My daughter bagged a cheap 980 just before Christmas as her 770 was playing up, it seemed to fix the issue. I finally got round to taking it apart to find it had next to no TIM on it (had it from new). I've retimmed it and cleaned the heatsink etc. It's now happily spinning away on unigine heaven 4 at 70c but is there a newer prog that would give it a better work out.
Heaven still pushes GPUs pretty hard, but there's also Valley and Superposition from Unigine. Of course, there also the 3D mark suite, among others.
