Undervolt Help

[SilveR41]

Can someone explain to me how is it possible that with an undervolt of 806mV and 1800MHz, my Gigabyte RTX 3080 Gaming OC Rev 2.0 is getting hotter than the stock settings?

 

[WereCat]

Compare power usage and fan speeda

[Eigenvektor]

1 hour ago, SilveR41 said:

Can someone explain to me how is it possible that with an undervolt of 806mV and 1800MHz, my Gigabyte RTX 3080 Gaming OC Rev 2.0 is getting hotter than the stock settings?

Undervolting on its own is similar to overclocking. It means your card will draw less power at the same speed, but if the power limit stays the same as before, it simply allows your card to clock higher before it runs into the power limit.

 

I don't know the exact physics behind it, but heat scales based on power draw and clocks (and some other factors). Since power draw is the same and clocks go up, heat output goes up.

 

If you want your undervolt to reduce power draw, you need to combine it with a power limit. Right now you should be getting more performance at identical power draw. Depending on how you adjust things, you can get the same performance as before at less power draw, or something in between.

[SilveR41]

2 minutes ago, Eigenvektor said:

Undervolting on its own is similar to overclocking. It means your card will draw less power at the same speed, but if the power limit stays the same as before, it simply allows your card to clock higher before it runs into the power limit.

 

I don't know the exact physics behind it, but heat scales based on power draw and clocks (and some other factors). Since power draw is the same and clocks go up, heat output goes up.

 

If you want your undervolt to reduce power draw, you need to combine it with a power limit. Right now you should be getting more performance at identical power draw. Depending on how you adjust things, you can get the same performance as before at less power draw, or something in between.

I realized that even if I Undervolt at 1700mhz, the GPU won't get higher than 1550mhz due to thermal throttle, I did the same benchmark like 4-5 month ago, and it was fine at 65 degrees and 1800mhz, does room temperature affect that much?

[Eigenvektor]

3 minutes ago, SilveR41 said:

does room temperature affect that much?

Yes. Fans work with ambient air. The warmer that air is (the lower the delta between air and the thing you're trying to cool) the less cooling can get done. So if it's summer where you are, stuff will get hotter overall.

[SilveR41]

5 minutes ago, Eigenvektor said:

Yes. Fans work with ambient air. The warmer that air is (the lower the delta between air and the thing you're trying to cool) the less cooling can get done. So if it's summer where you are, stuff will get hotter overall.

My room temperate is like 30+ degrees now, and when I did the benchmark last time like 12-15

[Eigenvektor]

29 minutes ago, SilveR41 said:

My room temperate is like 30+ degrees now, and when I did the benchmark last time like 12-15

Yeah, that's quite a difference. You should expect stuff to be around that difference warmer. So if your room goes from 15 to 30, your GPU is likely 15° warmer as well (~edit: or it would be if thermal throttling didn't happen).

[PDifolco]

49 minutes ago, SilveR41 said:

My room temperate is like 30+ degrees now, and when I did the benchmark last time like 12-15

You're outdoors?

[Mark Kaine]

1 hour ago, Eigenvektor said:

Undervolting on its own is similar to overclocking. It means your card will draw less power at the same speed, but if the power limit stays the same as before, it simply allows your card to clock higher before it runs into the power limit.

 

I don't know the exact physics behind it, but heat scales based on power draw and clocks (and some other factors). Since power draw is the same and clocks go up, heat output goes up.

 

If you want your undervolt to reduce power draw, you need to combine it with a power limit. Right now you should be getting more performance at identical power draw. Depending on how you adjust things, you can get the same performance as before at less power draw, or something in between.

That seems to heavily depend on the specific card (and maybe other factors) tho, my Gigabyte 3070 was undervolted pretty sloppily, 930v and "2010mhz" (way above stock) and ran considerably cooler than stock (while drawing at least as much power max)

Like 83c vs 71c (roughly)

 

Fancurves sure, the stock fancurves are dog, so that could be a factor too, I agree.

 

[Eigenvektor]

50 minutes ago, PDifolco said:

You're outdoors?

12–15 certainly sounds cool, bad isolation might do the trick? Living under the roof myself, I can get 30+ during summer

[leclod]

3 hours ago, Eigenvektor said:

Undervolting on its own is similar to overclocking. It means your card will draw less power at the same speed, but if the power limit stays the same as before, it simply allows your card to clock higher before it runs into the power limit.

I think this is wrong (at least under normal circonstances).

Look at the curve, 1800Hz is the top and it's not a high top

Edited July 18, 2025 by leclod

[leclod]

3 hours ago, SilveR41 said:

the GPU won't get higher than 1550mhz due to thermal throttle,

I'm not familiar with the 3080 but this doesn't sound right.

I'd consider repasting and undervolting to lower the temps.

Edited July 18, 2025 by leclod

[SilveR41]

3 hours ago, Mark Kaine said:

That seems to heavily depend on the specific card (and maybe other factors) tho, my Gigabyte 3070 was undervolted pretty sloppily, 930v and "2010mhz" (way above stock) and ran considerably cooler than stock (while drawing at least as much power max)

Like 83c vs 71c (roughly)

 

Fancurves sure, the stock fancurves are dog, so that could be a factor too, I agree.

 

Honestly I think I'm doing something wrong, if I set it to like 805mV and 1800MHz it's hotter than stock, which is the same MHz and more mV

[SilveR41]

2 hours ago, leclod said:

I'm not familiar with the 3080 but this doesn't sound right.

I'd consider repasting and undervolting to lower the temps.

I considered also changing the thermal pads, but the measurements I found for those aren't consistent, I mainly don't want to change the thermal paste cause if I damage a thermal pad It can get even worse

[leclod]

5 minutes ago, SilveR41 said:

I considered also changing the thermal pads, but the measurements I found for those aren't consistent, I mainly don't want to change the thermal paste cause if I damage a thermal pad It can get even worse

You could repad even without definite information.

Get 1mm, 1.5mm, 2mm pads. This should cover it.

Worst case you stack them.

Having a caliper will help measuring the current pads.

(damaging a pad isn't the end of the world, their integrity doesn't matter much as long as they are there)

Edited July 18, 2025 by leclod

[SilveR41]

3 minutes ago, leclod said:

You could repad even without definite information.

Get 1mm, 1.5mm, 2mm pads. This should cover it.

Worst case you stack them.

Having a caliper will help measuring the current pads.

(damaging a pad isn't the end of the world, their integrity doesn't matter much as long as they are there)

I saw people complaining about the stock thermal pads, so I might change those too, know any reliable brand?

[Mark Kaine]

2 hours ago, SilveR41 said:

Honestly I think I'm doing something wrong, if I set it to like 805mV and 1800MHz it's hotter than stock, which is the same MHz and more mV

Yeah but you maybe do something else as well as that alone should just make it probably slow... and cool ?

 

What about memory, is that overclocked? I'd leave that at stock or even lower it a bit, iirc memory on the 3080 runs really hot ...

 

[Salted Spinach]

You took screenshots at 12% GPU load with the undervolt curve, and at 1‰ GPU load with the stock curve

[SilveR41]

10 hours ago, Mark Kaine said:

Yeah but you maybe do something else as well as that alone should just make it probably slow... and cool ?

 

What about memory, is that overclocked? I'd leave that at stock or even lower it a bit, iirc memory on the 3080 runs really hot ...

 

At first, I overclocked it, then I saw it really impacted thermals and try underclocking it, guess what, nothing new, the GPU still overheats, I saw people talking about the trash thermal pads on this GPU, so I ordered new ones, I'll change those, re-paste the GPU and see what happens 

[SilveR41]

I changed the thermal pads and repasted the GPU, now it reaches 1800mhz on 3d mark and doesn't pass 73 degree on fur mark, also the VRAM runs MUCH cooler, I used Arctic MX-6 for the thermal paste and Arctic TP3 dor the thermal pads