capac1982 Man, I'd love to know this too. 

 
Hey mate ... here are measurements for the pad heights on the EVGA 3080 ti XC3 model (should apply for all XC3 models).  See below for more comments regarding pad dimensions and sources for both quality pads and also putty should you want to continue using thermal putty where applicable:
 
(thanks and shout out to Reddit user u/CriticalQuartz for the below image which I borrowed from his website, Kritical Pads)



Direct Link to Image

 
Before modifying a new/warrantied EVGA GPU?
 
Before modifying your GPU in any way, I would definitely recommend buying a replacement kit of both stock EVGA thermal pads as well as EVGA's own thermal putty on the chance you might ever have to return your card for warranty service. In such a case, you will want to return your card to it's factory pad/putty configuration.   I have read numerous personal accounts of EVGA not honoring warranty claims when GPU's have been shipped back to them with aftermarket thermal pads/putty installed and especially in cases where users decide to use thermal pads in place of the stock thermal putty that is applied to all EVGA 30 series VRM areas.  Both EVGA thermal pads and thermal putty are very affordable.  For EVGA thermal pads, you must email support directly; they run about $10 for a full set (minus VRM putty).  For EVGA thermal putty, you can purchase it online HERE.

  
For Aftermarket Pad Replacements?
 
1. Kritical Pads:  this fellow is offering pre cut sets of high quality, 20 W/mk pads for EVGA 3080/3080ti/3090 cards.  He's spent a good deal of time sourcing custom measured and cut pads and sells complete sets for these cards. Prices are quite reasonable and reviews so far have been very good.  I have a set I ordered for my EVGA 3080 ti XC3 Ultra Gaming but have not installed them yet as my VRAM temps are fine at the moment.  They do come well packaged and the overall quality of sizing and cutting are top notch.  Way better cuts than the stock EVGA pads I ordered (no offense to EVGA but the pads I ordered from them look like they were cut out with scissors whereas Kritical pads are obvously machine cut/manufactured). 


2. Direct from EVGA: you can order thermal pads for your specific GPU direct from EVGA if you are a registered.  Cost is only $10.00 (as of Nov 2021) so an excellent source, especially for taking your own measurements of pad dimensions for use when doing thermal pad replacements. 
 
There are also other good pads from the likes of Thermalright, GEilid, Alphacool and others so search about but the above linked Kritical Pads are a sure bet as they come in very precise, pre cut kits for most EVGA 30 series cards, taking a lot of the work out of thermal pad replacement.  Fujipoly is also a high quality pad but is a very hard material and does not easily compress and so other, more compressible pads are generally recommended to most completely fill gaps.
 

For Thermal Putty?
 
1. T-Global TG-PP-10 Silicone Thermal Putty : this is an excellent replacement for the stock EVGA supplied putty.  It's rated at 10 W/mk thermal conductivity and has been around for a good while.  There are lots of reviews on youtube and the like.  


2. Direct from EVGA:  EVGA also can provide their own thermal putty should you desire such and though not as highly rated, it will most likely be cheaper than the T-Global putty.
 
Best regards,
~s1rrah
 
 

s1rrah
 
Before I ordered the Kritical pads I had just re pasted the GPU core with Noctua NH-1

Yeap, also what I use, pretty much as good as NH-2 but 70% price.
 

s1rrah
The backplate gets so damn hot that I wonder if adding one of those copper heatsinks and Aliexpress might actually help the overall GPU temps... 

 
Also my experience. I have a 3080 non-TI which has 2 less front VRAM pads empty (the ones on the top) and actually I have both cheap thermal pads stacked on my XC3, and I also took some raspberry pi heatsinks I had lying around and glued them to the backplate atop the place where pads are. Doesn't help that much, actually think it's worse on the XC3. Also have Gelid Extreme 3mm (12mK/W) on the 3080 FTW3 hybrid, and also doesn't make much of a difference, maybe 2C at an ambient temp of about 20C which I guess is better than my results on the XC3.
 

s1rrah
I want to eventually install the hybrid kit on this 3080ti

 
I wouldn't, but at least you have a choice. My experience with the 3080 FTW3 Hybrid is overall bad: I have horrible pump noise just 5 months in, using the rad atop the pump all the time as I have an inverted case. In regards to VRAM, the hybrid kits are bad because the water cooling isn't direct but through a mounting plate that needs to be pasted, and the air from the auxiliary, on-board fan isn't guided through the board but towerds the holes on the PCB, so there's really worse cooling on VRAM and other components of the board besides the GPU chip. The only good thing is that the AIO actually works well enough that the GPU dissipates enough to compensate, as it is the main heater on the PCB.