Thermosiphon: The AiO prototype does not require a pump

YouTuber and speedster Roman Hartung alias der8auer received a prototype of a cooler based on the thermosiphon principle from Wieland, a supplier of semi-finished products made of copper and copper alloys as well as other materials such as aluminium, titanium or steel. In principle, the cooler works exactly like the IceGiant ProSiphon (test), but the condensing unit is located separately in the cooler and is not part of the tower.

The thermosyphon works somewhat like a heat pipe. The liquid evaporates due to the waste heat generated by cooling the chip and then condenses again in another area. The condenser flows back and can then absorb the waste heat. If this is implemented as a two-stage solution, the substance in the cycle is found in two physical states: liquid and gaseous. At the beginning of the video, it's not clear whether Wieland's prototype isn't entirely dependent on the fluid circulating in the circuit. Such an implementation would also be possible.

Since it is a prototype, the design initially does not play any role in consideration. The cooler that is placed on the processor is made of aluminum.

A Corsair iCue AiO cooling system with a 240mm radiator was used for comparison. In gaming testing, the Wieland prototype performed very well with CPU temperatures that were 8-9°C higher, considering no pump was used here.

In full load scenarios, a consistently used Ryzen 9 7950X achieves a load of just over 200W, which is of course related to the temperatures achieved when using Corsair's AiO. With the Wieland thermosyphon, the Ryzen 9 7950X gets close to 170W between Cinebench R23 runs. This of course affects the rhythm. With the Wieland cooler, the Ryzen 9 7950X's clock speed is a few hundred MHz lower, which is also reflected in lower multi-threaded performance.

The question now is how much potential do you want to attribute to cooling. On the one hand, the radiator or base plate can be made of copper. There is definitely still potential for improvement with the cooler.

The advantage of the thermosiphon is obvious: except for the fans, no active components are used. First of all, the pump is eliminated and this is largely responsible for the AiO's cooling volume. In addition, this pump is often the cause of malfunctions.

It remains to be seen whether the Wieland thermosiphon will be available in this form or from another manufacturer as a finished product. Limitations on dissipation power consumption would likely conflict with this, unless a way could be found for such a solution to be able to permanently dissipate 250 watts or approximately that level of waste heat.