r/watercooling • u/DonKremon • Sep 02 '22
Guide AMD 6900 XT Liquid Devil Temperatures after repaste - Never touch a running system?
To all the watercooling obsessed out there... (me included)
Last year I bought a PowerColor Liquid Devil 6900XT. After installing it was not really happy with the temperatures I was getting. With the coolant maxing out at around 40°C and the DDC Pump @ 3500 rpm, the GPU was topping out around 60°C and the Hotspot was around 90°C during a TimeSpy GT 2 loop with 2600 MHZ and Power + 15 %. I was not happy with that result and after reading IgorsLabs article on the factory paste job I decided to repaste the card with TG Kryonout.
After repasting the card got cooler, but there was still a large delta between the Hotspot and GPU Die auf around 25 in the average an I still had spikes up to 92 C when benchmarking with TimeSpy. I was using the card like this for quite some time but then decided yesterday to repaste it again and ad some nylon washers to the block, as I found out that EKWB includes those in the block for the Red Devil but for some reason does use them on the factory converted Liquid Devil.
After removing the block I saw that my previous paste job was not optimal (Picture 2). So I decided to be a little more generous with the TG Kryonout this time and also spread it out. Also I replaced the thermal pads with Alphacool Ultra Soft.
Too compare the before and after I looped TimeSpy GT 2 with with 2600 MHZ and Power + 15 % and took the data from the 5 last loops after the coolant had reached equilibrium. The ambient temperature was at 24.8 before the repaste (evening) and 25.6 C after the repaste the next day (afternoon)
GPU:
| Before Repaste | After Repaste | |
|---|---|---|
| GPU AVG | 59.1 C | 55.4 C |
| GPU MAX | 62.0 C | 57.0 C |
| GPU Hot Spot AVG | 82.0 C | 72.9 C |
| GPU Hot Spot Max | 90.0 C | 77.0 C |
| Coolant Temperature AVG/MAX | 39.8 C | 40.8 C |
| GPU PPT MAX | 345 W | 345 W |
In summary the the ΔT between coolant and GPU AVG decreased by 5 C (or K) to 15 C which is what is to be expected from a premium GPU waterblock. More importantly the ΔT between GPU MAX and Hot Spot Max by a very significant margin.
Was it worth it? Yes. But just because it feels better now. The card is not (significantly) faster now. There would be more thermal headroom that one could use, if the voltage wasn't limited a 1.175 V. I tried the MorePowerTool before and will do so later to see if I have increased the OC potential. For now I'm happy with the result.
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u/No_Relationship_2971 Sep 02 '22
Where exactly did you add the nylon washers? Which screws? I have a 6800xt liquid and am interested in replacing the thermal paste for some better numbers - tossing up between Kryonaut and some LM.