Yeah sounds like the new card was the scapegoat!
I mean, not intentionally so... but yes. I think it's actually working fine, especially now we know that the heatsink on this model is indeed meant to curve. It was doing a perfectly good job in the two games I tried (WoW and Elite Dangerous) - outside of the system crashes, which I now don't believe were it's fault.
Just because the PSU is new does not mean its not faulty, or gone bad. try old PSU with old GFX card and see if stability returns.
I'd swap back to the seasonic and try that. 5 years is nothing really, given that Seasonic probably had 10 year warranty period anyway.
I did, it crashed as well
I've had bluescreens with:
new psu + new gpu
new psu + old gpu
old psu + old gpu
Did not try old psu + new gpu because of recommended minimums.
At this point I don't know if there's a hardware fault elsewhere, or Windows had really gotten itself in a tizzy. Somewhere along the way Windows stopped booting entirely and just sat on a black desktop forever. Repair did not repair.
Currently running Prime 95 on a completely fresh windows install with just the iGPU and 2x m.2 ssds, no extras at all, only software is Corsair Link so I can turn the cooling up to max. I'll start adding bits back if it survives an hour or so; other storage drives, soundblaster fx, and probably the old GPU because I know that's been fine for years.
If all
that builds and runs cleanly for a couple of days, then I'll consider another fresh install (or system restore to clean state) with the new card. Don't really think there's a fast way to go about this, just going to have to be scientific with it and not change too many variables at once. Although one variable I have changed, now I think on it... the CPU 8-pin power cable is now in a different outlet on the PSU. But it would be fine if one of them turns out dodgy; I am never going to run a GPU that needs multiple power connectors, and if I do, a new power supply isn't so bad.