Why undervolting doesn't change my gpu temp?

James

Why undervolting doesn't change my gpu temp?

I just learned how to do undervolt  with msi afterburner.

I redueced The voltage -75mV with the same GPU clock speed.

But the memory temp still running the same 66-70c as before when rendering.

Is there like a diminishing point? Like when the temp already at certain point, undervolting won't do anything.

 

WendyLuvsCatz

that's not hot for rendering so don't worry

 my old 980Ti used to run at 90C, they are designed to cope with high temps

it does reduce the board power draw and your electricity bill considerably though

I do it because my PC will blackscreen otherwise as my PSU is insufficient

ed3D

WendyLuvsCatz said:

that's not hot for rendering so don't worry

 my old 980Ti used to run at 90C, they are designed to cope with high temps

it does reduce the board power draw and your electricity bill considerably though

I do it because my PC will blackscreen otherwise as my PSU is insufficient

+ 1 

outrider42

That is probably because Iray itself is not using your GPU's full power, even though it technically is 100%. It is hard to explain, but consider that a lot of software like video games pushes data across the bus constantly. But Iray is not doing this. Once Iray loads up the data in VRAM, that data basically stays there while it processes. It is not seeking out new data during the render, it can't, and this is why Iray fails to render on GPU if you run out of VRAM. Moving data takes energy to do, so when games push data over the bus that uses more energy. Remember the PCIe bus itself is rated for 75 Watts.

So undervolting might not have any impact on Iray until you turn it much farther down. It can depend on the GPU. The 4000 series in particular has already been shown to use a lot less power when rendering Iray versus gaming. We have users reporting their 4090 only uses 283 Watts with Iray, this is a card rated for 450!

I bet if you play a demanding video game with an uncapped frame rate your GPU will get warmer than it does with Iray. 3DMark has some benchmarks which can do this, too. This is where you will notice your undervolt the most.

James

I see.

Well, -75mv that's my card limit. More than that, it crashes.