GPUs are not mechanical parts (well save for the fans but those can be replaced). I would imagine thermal stress from heating and cooling would be the biggest issue - you don't get that under constant load.

Heat = bad for silicon. Also electromigration. And probably a couple other effects I don't know about.

Heat is bad, but MTTF at usually achievable temperatures is hundreds or thousands of years.

Electromigration matters on the order of 100 years.

Well, tell that to my chipset's SATA controllers (Sandbridge generation).

Intel messed up their life expectancy calculations, and thus they died after 2~3 years. I think 2 are still alive.

The Sandy Bridge SATA issue did make big waves back then and Intel did a recall IIRC.

Only the B2 stepping of chipsets should be affected by this tough.

https://www.anandtech.com/show/4142/intel-discovers-bug-in-6...

https://techreport.com/news/20326/intel-finds-flaw-in-sandy-...

I guess I should have gotten a replacement board.

I'll probably just upgrade to Zen3 soon, so it'd not be worth the effort (the machine in question is off and in storage).

Looks like you should have put a fan on that chipset. Like your GPU, which runs at extreme temperatures for extended periods of time!

It was cooled by the OEM config. And the chipset did get nice airflow.

Huge difference in wear, yes. But not in the direction you think, I think. Warming up an cooling down is more damaging for a card than running constant temperature. It 'jiggles' parts more.