lophilip
This has been posted on another message, so this is repeat:

For EVGA 3090 FTW:
Do not use thermal pads, they do not perform as well as the stock thermal putty that EVGA uses. I tried various thermal pads (over $100 worth) and I could not get better memory junction temperatures then stock. You must use thermal putty.

This is what I used TG-PP10-50 (if you are American, use digikey.com web site to buy. I used digikey.ca to buy):



It's expensive, but it works way better then thermal pads. You will need lots, it took 20g just to do the backplate. If you're redoing the entire card order 50g (maybe even 100g).

For the GPU use a good thermal paste, like noctula.

Edit:
for some reason I can't post a URL link to digikey. I will post picture.

mikeonex
Hey guys, 
 
I am instaling a Bykski combo waterblock and active backplate on a 3090 FTW3, I would like to use the putty "TG-PP10-50" but it's out of stock in Europe. I cannot find it anywhere.
Can someone link me to a website when I can order it ? even from the US digikey link seem to not work for me only europe version works and are out of stock

edgeofsanity
I picked up where the OP left off on this today. I had an Optimus block on my ftw3 3090 and needed to return it to stock today. I have a strix that is a much better overclocker that is replacing it now that I have another Optimus block.

Anyways, I've repadded several 3080s/3090s already and I use calipers to measure factory pads before replacing. Memory is 1.9mm-2.1mm with an average of 2mm. This includes backside, no difference. Always measuring the thickest part of each pad. Vrms are 2-2.3mm with an average of 2.2mm for the thickest parts. I suspect the vrms were the OPs problem.

I use thermalright oddessy 12.6wmk pads, these work great but are stiff and don't like to squish so you cannot use measurements for squishy pads.

For my repad I used 2mm on the front and back mem, 2mm on the vrms, and 1mm on the mosfets. For the VRMs you MUST use a bead of thermal paste or even better if you have thermal putty. You will not get good vrm contact if you don't do this. I used arctic mx4 for this. A 2.5mm pad is too thick. The paste fills the tiniest gap you'll have. This also let's the mosfets make contact with the pad unlike the OP where they have a gap. Core was pasted with TG kryonaut.

I'm still testing but results are great so far. Looping heaven in my open air testbench with the xc3 bios and power sliders maxed(~520w)core temps top out at 70c, mem junction 78c. Hottest vrm reading is 69c. Mining eth tops out mem junction at 92c. I can easily drop this 10c by pointing a fan at the backplate.

lophilip
This has been posted on another message, so this is repeat:

For EVGA 3090 FTW:
Do not use thermal pads, they do not perform as well as the stock thermal putty that EVGA uses. I tried various thermal pads (over $100 worth) and I could not get better memory junction temperatures then stock. You must use thermal putty.

This is what I used TG-PP10-50 (if you are American, use digikey.com web site to buy. I used digikey.ca to buy):



It's expensive, but it works way better then thermal pads. You will need lots, it took 20g just to do the backplate. If you're redoing the entire card order 50g (maybe even 100g).

For the GPU use a good thermal paste, like noctula.

Edit:
for some reason I can't post a URL link to digikey. I will post picture.

edgeofsanity

CBSloth
Hey, I'm just wondering what version 3090 ftw3u you had. I'm currently waiting for a replacement 3090 ftw3u due to an unbalanced power delivery on the early version card(nov 2020) I'm rmaing which had me pulling 85+W through my mobo pcie slot. With the 500W xoc bios I was only able to reach 448W max board power draw.

Did you go through the rma process for one of the newer revisions of the card or did you purchase a 3090 more recently?

 
This is an RMA card, I think I did it back in February of this year. I also had a Nov 2020 card for my original. Fan controller broke on the original right before my block came. Serial on the new one starts with 2114.
 

ordimans

edgeofsanity
I picked up where the OP left off on this today. I had an Optimus block on my ftw3 3090 and needed to return it to stock today. I have a strix that is a much better overclocker that is replacing it now that I have another Optimus block.

Anyways, I've repadded several 3080s/3090s already and I use calipers to measure factory pads before replacing. Memory is 1.9mm-2.1mm with an average of 2mm. This includes backside, no difference. Always measuring the thickest part of each pad. Vrms are 2-2.3mm with an average of 2.2mm for the thickest parts. I suspect the vrms were the OPs problem.

I use thermalright oddessy 12.6wmk pads, these work great but are stiff and don't like to squish so you cannot use measurements for squishy pads.

For my repad I used 2mm on the front and back mem, 2mm on the vrms, and 1mm on the mosfets. For the VRMs you MUST use a bead of thermal paste or even better if you have thermal putty. You will not get good vrm contact if you don't do this. I used arctic mx4 for this. A 2.5mm pad is too thick. The paste fills the tiniest gap you'll have. This also let's the mosfets make contact with the pad unlike the OP where they have a gap. Core was pasted with TG kryonaut.

I'm still testing but results are great so far. Looping heaven in my open air testbench with the xc3 bios and power sliders maxed(~520w)core temps top out at 70c, mem junction 78c. Hottest vrm reading is 69c. Mining eth tops out mem junction at 92c. I can easily drop this 10c by pointing a fan at the backplate.

Hello bro
 
Can you share a picture ?


I put thermal putty from TT Global on VRM
ANd i used gelid extreme for others, but i am at 108C during mining (with hybrid kit)....
 
On the backplate, should i use thermal putty too ?

Sure. I didn't use putty on the backplate or anywhere else. Just the 2mm and 1mm thermalright pads and that bead of arctic MX4 over the VRM pads.
 

 
Not the best pic but there isn't much squish on that VRM pad. 

 
One of my mining rigs, GPU #3 is this one. 90F ambient, fan blowing directly at the backplate. GPU 1 an 2 are stock, GPU 0 was a repad that needs to get redone. Mem temps are good but core contact isn't great so its 10C hotter than the others.