RTX 3080 undervolting adventures

[Mussels]

i've seen that too, actually

 

[londiste]

Do you have any idea why my voltage curve keeps changing slightly every time I restart my computer?

While I do not have a good source, my experience says the frequencies GPU uses are not exact and there are 12-15 MHz steps. If your curve points are set to specific values between two possible frequency steps, it might choose a slightly different frequency each time. As for the curve, no real idea. Might be due to the same stepped frequencies because the curve seems to be derived from less points than what is shown on the graph and the rest are extrapolated.

 

[nguyen]

yeah it's an annoying behavior, basically the curve will re-adjust itself at higher temperature (Initially at around 40C and every 10C after that).
You have to set the curve when the GPU temp is below 40C or possibly below 30C and save the undervolting profile, It will become the base profile and when the curve re-adjust itself, reloading the profile will fix it.

 

[Asryan]

Hi,

On most guide i've seen that before setting the voltage curve it's recommanded to lower the core clock to -200, and other did -300, what's the point of it?

 

[nguyen]

Hi,

On most guide i've seen that before setting the voltage curve it's recommanded to lower the core clock to -200, and other did -300, what's the point of it?

When undervolting, you want all the freq/voltage points become a straight line after the voltage that you want the GPU to maintain, instead of dragging every single voltage point to the same frequency manually, there are 2 fast ways of doing that:
1. set the core clock to -300mhz, drag the voltage point to the freq you want and hit apply
2. Hold Shift + Left click and drag to highlight from the desired voltage until the end, select the voltage point you want, hold Shift + Enter

For example this is an undervolt at 750mV

 

[Asryan]

Thanks unjust didn't get the - 300 at first thanks

 

[ewitte]

I undervolt my 3080 because I'm very sensitive to noise. I've tweaked it so that it is pretty much the same as out of box performance though. I'm only running 59% power when mining though.

 

[Taraquin]

I undervolt my 3080 because I'm very sensitive to noise. I've tweaked it so that it is pretty much the same as out of box performance though. I'm only running 59% power when mining though.

Try setting a voltagecurve like the one nguyen showed, then you can mine and game at the same time I do that all the time. With pwr-limit gaming and mining at the same time is not possible. Running 1600-1700@750mv is possible on most Ampere GPUs, that gives you roughly 90% of stock performance. Set at framecap limit a bit below monitors refershrate aswell, then you get more hadroom for mining while gaming With DLSS on I now mine at half speed on my 3060ti while playing Cyberpunk capped at 60 fps

 

[Mussels]

Hi,

On most guide i've seen that before setting the voltage curve it's recommanded to lower the core clock to -200, and other did -300, what's the point of it?

makes the curve easier to set so you dont have to slide every single number down - you lower ALL of it, then raise it to precisely what voltage and clock you want as a "flat" curve at load, with idle being untouched

unlike lowering a power limit, this gives you the performance you want without bouncing around