Hi everyone,
 
I just wanted to share my results regarding my Thermal Pad / Backplate Mod. I hope it will provide some information (which I didn't find...) for some who are interested in this topic and think about to improve the temperatures / noise levels.
 
FYI: This is no professional testing or recommendation which I provide but I tried to do it as accurate as possible! And I know I have a small case with suboptimal airflow. (And under water... but I do not want to deal with it :)) 
 
First of all I have to say that I still had some of the parts (e.g. the expensive Enzotech copper coolers) from my previous Morpheus 2 build (1080ti). Unfortunately I think in this generation it will not be possible to change to this aftermarket cooler because of the increased Memory and VRM temperatures.
 
The EVGA is not a loud card but coming from the Morpheus 2 with 2x120mm quality vents which was unhearable it is a huge difference! So every bit would count...
 
As I didn't find any valuable information if it makes sense to make this Mod (mostly "... it will provide nothing on the EVGA...") I just wanted to try it because I already had the nice Enzotech copper coolers which I do not want to sell.
 
I will also provide pictures so you can see what I did. 
 
I used the following stuff:
Enzotech copper coolers: 1x BMR-C1L, 1x BMR-C1, 1x MOS-C10
Gelid Solutions: 2x GP-Extreme 3.0mm 12 W/mK 80x40 Thermal Pad
EC360: 1x Thermal adhesive Tape (3 W/mK) (as I used the Enzotech before I needed new tape)
 
For the assembly please look at the pictures.
 
As for the thickness: yes it is 3mm - but Pads which squeeze a little bit more easier will be the best to make full contact. I am not sure if the Gelid are the best option (as they squeeze only a little bit).
 
My System:
Fractal Meshify C, Ryzen 5800x, X570, RAM 3800Mhz CL 16 (tight timings) IF 1900, RTX 3080 FTW3 undervolted to 850mv - 1905Mhz, Memory +1000 (21Ghz) - yes, tested, stable and better than less Memory speed
 
As for the testing method:
1. I set all the fans (CPU, Tower, GPU) to a fixed rpm (in this case percentage e.g. for the GPU 60%, but above 80 degrees C it will ramp up - for later)
2. Ambient temperature was the same (before the Mod 22,8 C - after the Mod 22,9 C)
3. I heated up the system for at least 20 Minutes (3D Mark Stresstests)
4. Did one more Test for confirmation (do the same Test again and see if it does provide the same Results)
5. My Case was closed (as it would be later too)
 
So I have to say that I liked the results. It did provide quite a nice improvement!
 
I did the following Tests:
Time Spy Extreme Stress Test (but the Temps will go above 80C - so we have to consider fan Speeds too)
Fire Strike Stress Test (here we do not have the Temp problem - so best comparison)
 
My Results (Max Temperatures):
Fire Strike before Mod:
GPU1: 79,0C
GPU2: 84,0C
MEM1: 77,5C
MEM2: 78,0C
MEM3: 80,3C
PWR1: 75,7C
PWR2: 79,4C
PWR3: 83,1C
PWR4: 84,6C
PWR5: 76,2C
FAN RPM: 1298
 
 
Fire Strike AFTER Mod:
GPU1: 76,0C (-3,0C)
GPU2: 77,8C (-6,2C)
MEM1: 73,4C (-4,1C)
MEM2: 71,4C (-6,6C)
MEM3: 75,6C (-4,7C)
PWR1: 70,4C (-5,3C)
PWR2: 73,3C (-6,1C)
PWR3: 76,7C (-6,4C)
PWR4: 77,8C (-6,8C)
PWR5: 73,8C (-2,4C)
FAN RPM: 1297 (the same)
 
 
Time Spy Extreme before Mod:
GPU1: 82,0C
GPU2: 87,9C
MEM1: 80,3C
MEM2: 81,0C
MEM3: 83,2C
PWR1: 78,5C
PWR2: 82,4C
PWR3: 86,1C
PWR4: 88,2C
PWR5: 78,3C
FAN RPM: 1637 (!)
  
 
Time Spy Extreme AFTER Mod:
GPU1:  81,0C (-1,0C)
GPU2: 83,2C (-4,7C)
MEM1: 77,9C (-2,4C)
MEM2: 75,9C (-5,1C)
MEM3: 80,3C (-2,9C)
PWR1: 74,9C (-3,6C)
PWR2: 78,0C (-4,4C)
PWR3: 81,6C (-4,5C)
PWR4: 82,8C (-5,4C)
PWR5: 78,1C (-0,2C)
FAN RPM: 1467 (10% less !!)
 
 
So for me it was absolutely worth it. Up to nearly 7C in secondary temps is very good.
And I am fine with the 3C less GPU temperature too (as I did not do something specific here).
That means in real world less noise (see Timespy Extreme Stress Test) with better Temps.
 
But: you have to test with cheaper aluminium coolers. I just had the more expensive Enzotech lying around .. so.
 
I hope this provides some information to people who are interested.
 
 
Thank you!
 
 
Edit: I tried to provide the result pictures but due to restrictions I could only add the Fire Strike ones.
 
 

FINALLY the mod i have been waiting for. I probably go for thermalpad only
 
Can u test thermalpads only ?
 
what about this https://www.amazon.com/Th...=1605908678&sr=8-1

This is exactly what I was looking for. Thanks! I may try this.

@steamroller: you need two of these (sorry until now I cannot answer PMs due to not enough posts): 
 
Gelid Solutions GP-Extreme Thermal Pad 80 x 40 x 3.0
 
 

It was relatively simple. You have to hold two or three nuts with a small pair of pliers while disassembly.
3mm pads should fit! It is what I used.

What measures of thermal pad does it have inside? where the chipset is located, not where the back plate is

Is this very difficult to do? Does it void warranty?

Really is a good job, but the question is:
 
How to need to do this ..? in a card that cost a lot, EVGA need to improve the high temps on their cards.. and every owner dont need to expend money for that..