Thermal throttling at 38 °C

[zeroks]

The problem

My Quadro RTX 3000 Mobile thermal throttles under very specific circumstances at low temperatures such as 38 °C (48 °C hot spot).

Reproducible thermal throttling in 3 steps

1. Launch “Kingdom Come: Deliverance” (KCD)
2. Load save game right before the famous sermon cutscene
3. Start cutscene

Instant thermal throttling of the GPU starts at 38 °C (48 °C hot spot), while the CPU doesn't throttle:

Log output of GPU-Z shows PerfCap reasons 1 and 3 (see “GPU-Z - KCD cutscene.txt”).

(There are other cutscenes that cause GPU throttling, mostly those with lots of NPCs, however, most don’t.)

Reproducible absence of thermal throttling

Setting an FPS limit of 20 FPS for “KingdomCome.exe” in NVIDIA settings prevents GPU throttling. This holds true even if temperatures reach 43 °C (53 °C hot spot), which is hotter than during the above unlimited test run.

Throttling does occur when limiting to 60 FPS.

Thermal situation apart from specific KCD cutscenes

I can run Unigine Heaven indefinitely at temperatures of up to 61 °C without GPU throttling.

I can run Unigine Heaven and TS Bench indefinitely at the same time at GPU temperatures of up to 69 °C (79 °C hot spot) and CPU temperatures of up to 94 °C with much less GPU throttling than during the cutscene:

Again, log output of GPU-Z shows PerfCap reasons 1 and 3, but way fewer threes than during the cutscene (see “GPU-Z - KCD cutscene, 20 fps.txt”).

I can run TS Bench indefinitely at CPU temperatures of up to 78 °C without CPU throttling.

Questions

Why does GPU thermal throttling occur at such low temperatures during the cutscene when it doesn't occur at much higher temperatures during Unigine Heaven?

Why is the throttling more severe during the cutscene at low temperatures than at much higher temperatures while running TS Bench and Unigine Heaven?

How can I fix this?

Thanks for reading. I hope you have a nice day.

 

[zeroks]

The same thermal throttling at low temperatures occurs when just launching Counter-Strike 2 and clicking around in the menu. During almost every transition between two screens throttling occurs.

I applied thermal putty and reapplied thermal paste. The previous coverage seemed to be complete and there was almost no excess paste. Afterwards, GPU (and CPU) temperatures are a few degrees lower, but there has been absolutely no change in regards to thermal throttling.

Before it had thermal pads:

Blobs of thermal putty:

Small excess after mounting heat sink:

Final result after removing excess putty: