Make sure to check Part 1 of this video ( link here - https://youtu.be/3wAuM8VDnbI ) which is a guide on how to Undervolt and underclock your GPU.
Some info about the testing, that I should have mentioned in the video.
PC
i9-10900k
Gigabyte Aorus Elite Z490
64gb DDR4 3200mhz
MSI Ventus 3X RTX 3090 OC
Lian Li Mesh II RGB Airflow case (side panel off)
Lian Li 360mm Galahad AIO
3 fans at front and top
5 mins per test for mining.
10 mins per test for gaming (Cyberpunk 2077). Default I did test for 30 mins just to make sure it was as hot as it could go.
PC is -
10900k @ stock
Gigabyte Z490 Aorus Elite
Lian Li Galahad 360mm AIO at the front of the case
3 120mm exhaust fans (two at top, one at the back)
Corsair Vengeance 64gb DDR4 3200mhz ram RGB
MSI Ventus 3X RTX 3090
Corsair RMx850 PSU
Lian Li Mesh II RGB Airflow case (left side panel off)