Has anyone tried out this furry little donut-shaped app for gpu stress-testing?
http://www.ozone3d.net/benchmarks/fur/
It's actually really good as a stress-testing tool, it turned up the heat on my geforce 9600 GT to temps I didn't think it would reach! And on top of that it showed plenty of artifacts during rendering at high temps which meant my OC'ing wasn't as stable as I thought it was.
Artifacts are things that pop up for just a split second, like black squares, white patches, or just dots like in this image:
I advise to anyone that has done gpu overclocking to try this out. It's free, and it may surprise you when you get it running. Remember that just because boinc doesn't complain (mine didn't!), it doesn't mean your gpu workunits are returning truly good results. (And this also applies for non-boinc projects).