Info RX 6900 XT easy pcb back thermal pad mod

[alceryes]

AMD reference RX 6900 XT.
Just did the quick-n-easy pcb back thermal pad mod. I went with the 'less is more' approach with the pads. All temps dropped nicely with the VRM temp going down 9ºC! I've left all OC and power settings at stock and the GPU core still peaks at 2500MHz. Extremely happy with the results. I'll probably start tinkering with small overclocks soon. Think I got lucky with this reference card.

Before adding thermal pads. Five Horizon Zero Dawn benchmark runs back to back (ultimate quality).

https://imgur.com/a/H85e2cr

View: https://imgur.com/a/H85e2cr


After adding thermal pads. Five Horizon Zero Dawn benchmark runs back to back (ultimate quality).

https://imgur.com/a/can7bMg

View: https://imgur.com/a/can7bMg


I used Gelid Solutions GP-Extreme 12W thermal pads. 3mm for the eight memory module areas and 1mm for the VRM components.

https://imgur.com/a/0mAisW2

View: https://imgur.com/a/0mAisW2


After some undervolting and a lite overclock I've got a 7% Time Spy graphics score improvement.

 

[Metal Messiah.]

Hmmm... This is interesting GPU modding work.

 

[Phaaze88]

How'd you go about selecting the current pads?
Changing pads should be easy, but things like thickness and hardness make things more difficult.

 

[alceryes]

How'd you go about selecting the current pads?
Changing pads should be easy, but things like thickness and hardness make things more difficult.

I just researched a bit.
Some people say that you only need 2.5mm under the memory module areas. Others say 3mm. Note that there are no memory modules on this side of the PCB. I'm just cooling the opposite side of the PCB right under where the modules are. The Gelid pads are very soft/compress very well so I went with the thicker pads. When I looked horizontally across the back of the PCB, with the pads on, the 3mm and 1mm pads were level with each other so I think I made the right choice.

From what I've read, AMD actually does a decent job with the front side of this card. They use a graphite thermal pad for the core and regular pads for the memory and VRM components. They just completely neglect the back of the card, even though they have a full aluminum shroud (heatsink) covering the entire back.

 

[Makaveli]

Very nice I was looking at doing something similar for my reference 6800XT.

I think i'm going replace stock cooling with an AIO though.

Alphacool Eiswolf 2 AIO - 360mm Radeon RX

I just ordered

LINKUP - Ultra PCIe 4.0 X16 Riser Cable so I can side mount it. Need to purchase the AIO next.

I'm going to use your post as a reference if I decide to use thermal pads during that install.

Did you see any temp reductions in the junction temp?

 

[alceryes]

Very nice I was looking at doing something similar for my reference 6800XT.

I think i'm going replace stock cooling with an AIO though.

Alphacool Eiswolf 2 AIO - 360mm Radeon RX

I just ordered

LINKUP - Ultra PCIe 4.0 X16 Riser Cable so I can side mount it. Need to purchase the AIO next.

I'm going to use your post as a reference if I decide to use thermal pads during that install.

Did you see any temp reductions in the junction temp?

Can you post your Time Spy run with this setup?

You'll definitely be able to take that RX 6800 XT to new heights with an AIO. I'm not ready to go that far with my 6900 XT. I paid a Hell of a lot of money for this card and I want it to be a 4+ year card. I'm gonna wait till I actually need more performance out of it before I start thinking of watercooling.

 

[Makaveli]

Can you post your Time Spy run with this setup?

You'll definitely be able to take that RX 6800 XT to new heights with an AIO. I'm not ready to go that far with my 6900 XT. I paid a Hell of a lot of money for this card and I want it to be a 4+ year card. I'm gonna wait till I actually need more performance out of it before I start thinking of watercooling.

Once I have it complete sure.

The Riser cable should be here tomorrow however the AIO once I order it has to ship from the US to Canada and i'm not sure how long that will take.

 

[alceryes]

You should have a before mod run too to see how much you gain.

 

[Makaveli]

You should have a before mod run too to see how much you gain.

Stock performance with reference cooler.

 

[alceryes]

Here's my HZD benchmark on Ultimate. (can't directly compare since different resolutions)

https://imgur.com/Hb7iY5G

View: https://imgur.com/Hb7iY5G

 

[Makaveli]

Here's my HZD benchmark on Ultimate. (can't directly compare since different resolutions)

https://imgur.com/Hb7iY5G

View: https://imgur.com/Hb7iY5G

Yup i'm on a ultra wide display.

The gpu driver version in your screenshot also looks older have you updated a new one yet?

 

[alceryes]

Yup i'm on a ultra wide display.

The gpu driver version in your screenshot also looks older have you updated a new one yet?

Some performance issues have been reported with the last couple drivers over at overclock.net so I'm sticking with this one for now.

 

[Makaveli]

Some performance issues have been reported with the last couple drivers over at overclock.net so I'm sticking with this one for now.

Got a link to that i'm on the newest beta right now and good so far.

 

[alceryes]

Bottom of this thread page is one post but if you go pages back there's continual discussion bashing the most current drivers.

https://www.overclock.net/threads/official-amd-radeon-rx-6900-xt-owners-club.1774299/page-291

 

[Kona45primo]

Nice work on the thermal pad mod, I'll be doing this eventually to my 6900xt. Thanks!!

 

[alceryes]

Did you see any temp reductions in the junction temp?

Forgot to answer this. Junction temps went down around 6ºC.
Also, this difference is probably a bit better than the HWiNFO64 above as ambient was a few degrees warmer when testing with the pads.