You are the wrong @soda37, copper shims are the best thing you can do to your 3080,3090 and 3070Ti graphic cards, you just need to do it the right way like
1. Make sure you use the exact thermal pad size to copper shims, if the thermal pad is 2MM make sure you use 2mm copper shims.
2. Some copper shims come with sharp edges, use sandpaper to smoothen the copper shims so that they will sit perfectly on the chips.
3. Use heat resistance tape like kapton tape to cover every space, capacitor and resistance around the mem chips just for safety purposes.
4. Use the thermal paste on the chips before adding the copper shims, you must add the paste to both sides of their copper shims before putting the heat sink on.
You will get a very good result, 30°C gone from mine after 110°C start showing on my 3070Ti and 3080, its been two weeks now, from 110°C to 76°C, fear is a bastard.
I like that reminds me of Dune's "...Fear is the mind killer..."
https://www.etsy.com/listing/564401088/printable-quote-frank-herbert-i-must-not?