Hmm, that mushta, gave me nonsense advice, I stand by this. It made my card run 10c hotter.
I worked out what happened. Because I pressed down hard on the card near the power connector when it was hot, the already runny Nvidia thermal pads compressed and smudged. I reckon that's what happend to my 3090 following mushtas advice.
I had no choice put to repad the card
.I bought 4 packs of Gelid extreme , to replace pads on the front and back of the card, cost £40 in total ( ripp off). I used all of the pads and they were just about enough ( 80x40s). They were 1.5mm. The whole replacement took hours.
Bit Glad that it fixed my card and un did Mushtas terrible advice. Now my card runs 2c-6c cooler than before on the T Junction, but 6c hotter on the core! Simply no where near the gains Internet trolls post to get more views on their videos (20c cooler wow!).
Putting screws underneath the card and claiming 20c drop, people who do that probably already had defective cards. I can see why miners are rushing to do this but for gaming it's just not worth all the hassle.