The source of the problem for the reference Radeon RX
Hardware

The source of the problem for the reference Radeon RX 7900 XT and XTX can be an evaporation chamber

AMD has not yet identified the cause of GPU overheating in some of the Radeon RX 7900 XT and XTX reference graphics cards. The well-known enthusiast Roman “der8auer” Hartung (Roman Hartung) conducted his own investigations and concluded that the evaporation chamber could be the cause of the problems – it has design flaws.

Keep in mind that some owners of the Radeon RX 7900 XT and XTX reference versions have complained about overheating and high noise levels in their graphics cards’ cooling systems. In particular, owners noticed a significant difference between the GPU’s average temperature and the temperature at its hottest point. Sometimes the difference exceeds 50 °C and reaches a value of 110 degrees at the hottest point. Because of this, the throttling mechanism kicks in and the GPU resets frequencies to avoid burning out.

Roman “der8auer” Hartung bought four Radeon RX 7900 XTX graphics cards to try to find the cause of the problem. Research using the Furmark stress test has shown that the way the graphics card is installed affects the temperature of the GPU. In a horizontal position, GPUs reach higher temperatures at their hottest point than in a vertical position.

    Graphs of GPU temperature changes for graphics cards during a stress test in a horizontal position

Graphs of GPU temperature changes for graphics cards during a stress test in a horizontal position

With two of the tested cards mounted horizontally, the GPUs quickly reached the temperature limit of 110 °C and began to drop frequencies. Finally, the fans on the horizontally mounted cards ran at “well over 2000 RPM” while in the vertical position they were around 1700-1800 RPM.

    Graphs of GPU temperature changes for graphics cards during a stress test in a vertical position

Graphs of GPU temperature changes for graphics cards during a stress test in a vertical position

Der8auer developed a special stand to see if the cooler’s weight and gravity could cause the higher temperatures in landscape mode, but performance remained the same. In addition, it has practically turned out that neither the additional plate for cooling the power subsystem nor the height of the mounting legs of the cooler bottom affect the contact of the cooler with the GPU.

Additionally, while one of the cards was being tested at Furmark, the enthusiast rotated the entire dyno, after which the GPU temperature increased significantly. And even returning to the original position did not result in a lower temperature, as shown in the graph below. The same issue has been observed on both modded and unmodified Radeon RX 7900 XTX reference cards.

There can only be one explanation for this behavior: There are problems with the construction of the evaporation chamber. While graphics cards typically don’t change position during operation, the finding suggests that the liquid in the vapor chamber may be having circulation issues. The enthusiast believes that this may be due to both a design issue and a material choice issue, but he’s pretty sure the problem lies in the vaporization chamber.

Keep in mind that AMD recently stated that it is aware of the overheating issue in the latest graphics cards and suggested that users who encountered it should contact support. But as Der8auer pointed out, if the vapor chamber is indeed the cause of issues with the Radeon RX 7900 XT and XTX, it could force AMD to take more serious action.