Unique power supply stress test discovered
I've stumbled across a PSU stress test combo that can be very useful in some cases. Finding it let me fully resolve an intermittent problem I was having.
I was exercising a new RTX 2080ti by running Furmark's "GPU Stress Test" in a 1366x768 window with 8X MSAA. The PSU was a high quality but very old BFG 800W unit, which had been powering a GTX 1080ti for 6+ months with no problems.
All was good until after a week or so the PC did an instant and total power-off, requiring wall power to be cycled. These shutdowns became more frequent, always when I ran some other app along with Furmark. It was likely that a PSU weakness was being exposed, but I couldn't rule out an issue with the new GPU. Unfortunately these crashes remained unpredictable and non-repeatable.
Then I happened to try O&O Software's free "ShutUp10" utility (along with Furmark). Nothing happened during normal use of this util until I dragged the right-side scrollbar down. Then the PC instantly shut down - and this was exactly repeatable over three or four more tries.
That convinced me that the problem was with the PSU, not the graphics card. I didn't think to try the 1080ti for comparison (...) but went ahead and installed a new Corsair HX1000 PSU, set for 'single rail' 12V. That fixed things - no more shutdowns with ShutUp10 nor with several taxing games running along with the Furmark window.
And note this: with the new PSU, when I drag the ShutUp10 scrollbar, I hear ticking noises from the machine. This only happens if Furmark is also running. I'm guessing that these sounds are the result of current spikes impacting the PSU's reactive components, and that the old BFG's filtering was no longer sufficient to prevent the transients from triggering a protection circuit.
I've now also tested Furmark and ShutUp10 together on two other PCs having a GTX 1070 and Corsair 500W and 600W power supplies. I get the same ticking sounds with these, but no shutdowns.
So it looks like these two apps together somehow create significant PSU transients. They would be useful if you suspect a PSU is failing but want proof, given that replacing one is a chore at best.