Anyone else fiddled with undervolting on a 4090? Is it as wonky as I've experienced?

[DaBadger84]

So I'm sort of copy/pasting a thread I posted elsewhere, some of the information is from last night, but I'm curious if anyone around here has played with it & if their results were equally as interesting & hard to get to apply at times.

Have you guys tried to undervolt you 4090 at all? I've found the whole thing in general can be kinda frustrating so far, mainly in the way of what I put in to the Afterburner curve is not what I end up running half the time. But, when it works... It's pretty great thus far.
My particular model is a rather beefy Gigabyte 4090 Gaming OC, the one with the notoriously "good" memory cooling.
I'll have to add screenshots when I can use my computer again (currently Port Royal Stress testing an "undervolt OC curve" that's running 2970MHz at 1070mV locked - I know, that shouldn't be a thing lol), but I've hit a few tested stable setups that I've gamed on & not had crashes (yet).

So this card runs at 2760-2805MHz stock with the stock voltage of 1050mV (with no voltage slider adjustment) and power limit maxed. That runs warm, but by no means hot hot, however it does draw slightly more than 450W at stock, if the power slider is maxed, and if I leave the power slider at 100%, it will occasionally tickle power limit & clock down to 2760 or 2745 more (this is on Port Royal testing).
Settings I have tested stable/gamed on with no issues so far (will add screenshots later) :

2790/2775MHz @ 975mV (so stock clocks but with a significant reduction in voltage - Note: the reason I list two clocks is it's set at 2790MHz but runs 2775MHz 99% of the time, this 15MHz downstep is common to all my settings) - this runs smooth as butter, and about 7-8C cooler, with apples to apples fan settings applied across the comparison. It also draws ~70W less power & scores the same/within margin of error.

2850/2835MHz @ 1000mV - slight OC, still a nice undervolt. Also runs cooler than stock (by about 5-6C) & lower power draw (about 50-60W less if I recall). I gamed on this for hours & it ran perfectly enough that I forgot I had it applied.

2895/2880MHz @ 1025mV - basically a 105MHz OC while still drawing less power than stock & running slightly cooler than stock. I don't recall exact numbers on this one off the top of my head, but I do have screenies I can get them from probably.

One tidbit I've found that's annoying is, apparently, because the stock curve is "flat" between 1025mV & 1035mV (meaning it runs the same core speed at both by default), it seems like because of this you cannot run an undervolt at 1035mV & have it STAY at 1035mV. I've tried all sorts of things, the goal was to try & get 2910MHz actual clock tested, but it keeps dropping to 1025mV & crashing about 7-8 loops in on the stress test because of it.

Right now I'm testing 2970 @1070mV like I said.. And it's now on loop 17/20, so it looks like it's gonna pass. With a toasty max temp of 65C on the core temp & 66-68C on the mem (should be noted the GDDR6X was at +1500MHz for all these test runs listed, cuz that's where I've tested it stable. It'll game on +1500 all day but 1600 is hit or miss in benchmark runs). - update on this, it did pass, I'll post screenshots shortly.

Toasty but consistent it was. This is basically the best I can get out of the card. I can run a +150/+1500 regular offset & be stable as well, but it runs just as hot, clocks lower when it heats up, and all that jazz. It's interesting that this even works though. You would think setting a voltage in the curve of anything over 1050mV wouldn't work, but it does. I haven't tested it without the voltage slider maxed.

Right now I'm working on retuning my cpu curve optimizer crap so I haven't fiddled with the gpu today. But I'm fairly certain I've found the upper (2970 @ 1070mV) and lower (2770 @ 975mV) limits of this card, within the allowed "stock" to maxed sliders settings. I'm sure I could go lower, but running at less than stock/default gpu cost clock doesn't appeal to me.

Here's the resulting stress test Temps from 2770MHz @ 975mV for comparison to what you run at "stock" if ya like:

https://i.ibb.co/JKGXhFX/GPU-Undervolt-OC-testing-2775-MHz-975m-V-GPU-Stress-Test-Pass.jpg

 

[trikats]

Yep, I experienced the same thing on my open box 4090 Gaming OC. Many times core will start out 15 MHz higher, then drop to set AB curve value.
Hits 2760 core at stock, but terrible at UV. Still in progress, but might be stable at 2655 .95V. Passes 3Dmark stress tests and gaming when clocked a smidge higher, but crashes Cinebench 24 (really puts GPUs through the wringer).
Stable around +1200 VRAM. Not interested in core OCing. Mine is kind of a dud for UV/OCing, but won't have the card for long so not concerned.
My 4070 Windforce OC will sometimes do something similar, but on certain MHz it will not fluctuate.
Quake II RTX Demo heats up the 4070 compared to other tests, but 4090 handles it well.

 

[GrumpyPants]

Yep, I experienced the same thing on my open box 4090 Gaming OC. Many times core will start out 15 MHz higher, then drop to set AB curve value.
Hits 2760 core at stock, but terrible at UV. Still in progress, but might be stable at 2655 .95V. Passes 3Dmark stress tests and gaming when clocked a smidge higher, but crashes Cinebench 24 (really puts GPUs through the wringer).
Stable around +1200 VRAM. Not interested in core OCing. Mine is kind of a dud for UV/OCing, but won't have the card for long so not concerned.
My 4070 Windforce OC will sometimes do something similar, but on certain MHz it will not fluctuate.
Quake II RTX Demo heats up the 4070 compared to other tests, but 4090 handles it well.

Hey, I literally registered an account just to point this out because I see this so often everywhere.
The numbers your card can run is absolutely not a dud.
There are so many misinformation out there with people saying their card are doing these insane numbers out of box and makes people think their 4090s are bad bins.
Most 4090s out of box run at the 2730-2775 range, the absolute highest I've seen with my own eyes do 2850 out of box and that's the one and only I've seen out of dozens of 4090s from various manufacturers that I've built and tested. If you go buy any 4090, 99% of the time you'll get one in the 2730-2775 range.
People are getting the out of box clocks confused with overclocks. Yes, most 4090 can get over 2900 mhz with an overclock at stock 1.05v, with some very very rare good bins doing 3ghz.
Most cards need voltage slider maxed out to 1.1v to do 3ghz, and some even rarer ones doing 3.1

 

[trikats]

Hey, I literally registered an account just to point this out because I see this so often everywhere.
The numbers your card can run is absolutely not a dud.
There are so many misinformation out there with people saying their card are doing these insane numbers out of box and makes people think their 4090s are bad bins.
Most 4090s out of box run at the 2730-2775 range, the absolute highest I've seen with my own eyes do 2850 out of box and that's the one and only I've seen out of dozens of 4090s from various manufacturers that I've built and tested. If you go buy any 4090, 99% of the time you'll get one in the 2730-2775 range.
People are getting the out of box clocks confused with overclocks. Yes, most 4090 can get over 2900 mhz with an overclock at stock 1.05v, with some very very rare good bins doing 3ghz.
Most cards need voltage slider maxed out to 1.1v to do 3ghz, and some even rarer ones doing 3.1

Here is the quote from my post "Mine is kind of a dud for UV/OCing."
Never said it was a dud on stock settings. Stock 2760 core is actually a smidge above average.
I also said "terrible at UV" "might be stable at 2655 .95V" "Stable around +1200 VRAM"
I'd say 2725 - 2750 at .95V is average, but 2655 is definitely on the low end hence "kind of a dud".
VRAM results vary wildly, I've seen many posts of +1700 thru +2000 stable, but also plenty of mediocre results. My guess is +1200 is slightly below average.
There isn't a database of 4090 UV so I base my estimates on posts I can find. Not the most accurate, but best I can do.