This is what I mean by running out of juice. Particularly the crashing when I attempt to run any kind of benchmarking.
NO, completely different. Crash / glitches can means “not enough power for the card”, but not “pulling too much from the PSU”
In cMP and MacOS, “not enough power” won’t happen unless you flashed a firmware that has incorrect voltage setting. (Or something like the 6pin / 8pin cable is faulty e.g. poor connection in one of the 12V pin. But this is not the cMP’s fault)
On the other hand, with a correct ROM, it can “pull too much power and shutdown the Mac”. You should not see any crash / glitches, but shutdown straight away. This can happen within a second, too fast that almost impossible to notice any abnormalities on the screen (if there is any).
The reason is because the 980W PSU is powerful enough to drive your card. So, never “not enough power”. But once your card keep pulling and reach the predetermined limit (about 120W on each mini 6pin). The SMC will shutdown the Mac without any warning.
For example. Your card need 100W from the 8pin, and it try to pull 100W from the 8pin. Everything should be ops normal, no glitches, no crash.
But once your card need 130W from the 8pin. It will try to pull 130W. The cMP won’t limit the power available to 120W (no “not enough power to the card”), but let it draw full 130W. And once reach the SMC limit, the Mac Pro shut itself down straight away.
So, in your case, I don’t think it’s power issue.
If you never try to re-sit the card. I recommend you try that. If your card can work before flash. Something is wrong, but should not be the setup, or ROM 2.
Re-sit, and give the slot a good blow occasionally can clear some strange issue. Worth to try with virtually zero cost.
