Question Best sweet spot clock speed for 4090? Undervolt

[Vetrix1996]

Currently running at 9.6v 2700mhz +1056 mem
Thinking of trying to bump it up to 2800mhz at the expense of more voltage if the performance gets a lot better, say by maybe 10 percent or something. What's the best "bang for buck" target mhz?

 

[Vetrix1996]

Sweet, TPU did a review on that one: https://www.techpowerup.com/review/zotac-geforce-rtx-4090-amp-extreme-airo/40.html
At 1.050v, 2805mhz looks to be the target max boost. Easy enough to figure out an UV for that one to let it sustain 2805 for longer.
Go ahead and do 2800 if you want, the card was already trying to do that.

I know but im trying to do it at lower power. Im at 9.95v

 

[Phaaze88]

I know but im trying to do it at lower power. Im at 9.95v

Apologies, but you mean 995millivolts or 0.995v. 9.95v = fried card.

Anyways, try more aggressive voltage offsets for 2805mhz: 1.050v - 0.06v, -0.07v, 0.08v, etc...
Beware, that it behaves strangely compared to increasing core and memory clock;
-if you increase core clock too much, it flat out crashes or crashes eventually.
-if you increase memory clock too much, it throws out artifacts.
-but UV too much, and it can 'phantom throttle', possibly not crashing at all. It's very hard to watch for, and what made me give up trying to find the lowest possible voltage for my gpu's max boost.