It turned out how replacing liquid metal with thermal paste in the GeForce RTX 5090 FE affects GPU temperature and performance

In the flagship GEFORCE RTX 5090 Founders Edition, NVIDIA uses the “liquid metal” thermal interface for the best thermal conductivity between the graphic processor and the alcohol of the evaporative chamber of the new Double Flow Throhh cooling system. As the Techpowerup experiment showed, replacing liquid metal with a regular thermal grease in fact does not slightly reduce the effectiveness of GPU cooling.

Image source: TechPowerUp

To prepare a review of the GEFORCE RTX 5090 Founders Edition video card, Techpowerup had to completely disassemble the video card to show its components and features. Then she, of course, had to be assembled back. Since the application of liquid metal requires a certain dexterity and caution, and takes more time, the journalist decided to use the Arctic MX6 thermal grease.

GPU sealing frame to prevent liquid metal from contacting other graphics card components

After assembling the video card, the reviewer ran tests again, which showed that with thermal paste, the temperature of the GB202 GPU in the GeForce RTX 5090 Founders Edition increased by only 2 degrees Celsius compared to liquid metal. In the graph below, you can see that the Arctic MX6 copes quite effectively with its task within the 370-second stress test, yielding only a couple of degrees to the liquid metal at peak load. However, what is striking is the fact that the starting temperature of a GPU with liquid metal is about 5 degrees Celsius lower than when using thermal paste.

The maximum GPU temperature during the stress test using thermal paste was 79.4 degrees Celsius, and with liquid metal – 77.6 degrees. An increase of 1.8 degrees can hardly be considered significant.

The performance of a graphics card with a thermal package was also checked. It turned out to be exactly the same as with liquid metal. Under a serious load, the card in both cases did not discard the GPU frequencies, and the chip temperature was below 90 degrees Celsius, which turned out to be within the normal range. TechPowerup explains that NVIDIA increased the threshold of safe temperature for the GPU RTX 5090. In the former RTX 4090, this threshold was 83 degrees Celsius, upon the achievement of which the chip began to discard frequencies.

Assembling and disassembling the reference version of the GeForce RTX 5090 Founders Edition turned out to be a difficult undertaking, TechPowerUp notes. The need to use liquid metal as a thermal interface would further complicate this process. Good news for those who are used to changing the thermal interface of a video card on their own – over time this will be required in any case. A thin layer of thermal paste will do the job just as well.