What is claimed to be "probably the most dangerous CPU cooler ever made," has been analyzed by extreme overclocking expert der8auer, on his YouTube channel. The danger with the cooler under the spotlight is that its ordinary-looking heatpipes are actually filled with liquid metal. However, this isn't the gallium-indium liquid metal der8auer often promotes as a great thermal interface material. Instead, the liquid metal in this CPU air cooler is an alloy of two highly reactive alkali metals: sodium and potassium.
The ~2010 vintage Danamics LMX Liquid Metal CPU Cooler is said by der8auer to have been an attempt to address the perceived underperformance of traditional heatpipes. The tech team at Danamix started testing CPU air coolers with liquid metal coursing through their veins in 2008 or earlier, but the LMX model you see pictured was being distributed in limited numbers in early 2010.
Der8auer checked some of the physical properties of sodium-potassium alloys to try and uncover the reasoning behind building the Danamix LMX. His research suggests the liquid alloy material's heat capacity is only a quarter that of water, but its thermal conductivity is a lot better, at about 30x that of water. The YouTuber reckoned that the second metric looks impressive, but isn't a useful quality for a liquid inside a heatpipe.
A complication of the Danamix LMX design is the requirement of a pump. Der8auer took the cover off the top-mounted pump and you can see it clearly in the image above. This is a neodymium electromagnetic pump and it is powered by some rather thick cables supplying 30 amps. To touch the cables were quite warm, estimated to be between 40 to 50 degrees Celsius.
The practical value of a technology should be observable by testing. Thus, der8auer set up a couple of test runs to compare the Danamix LMX to a Noctua NH-U12A air cooler, both using the 120mm fan from the Noctua.
In gaming comparisons, it was hard to compare the temperatures as they changed rapidly with the different game scenes and intensity of action. Cinebench testing gave a clearer comparison, and the Noctua was observed to be five to six degrees Celsius cooler overall. Der8auer commented that considering the age difference in the coolers, and the Noctua's high standing in 2023, the LMX didn't do too badly. However, the ordinary heatpipe "was definitely superior" to the sodium-potassium alloy-filled rival in his judgment.
We don't really know whether the uninspiring performance of the LMX was instrumental to Danamix's demise. However, the company would go into liquidation later in 2010. It is thought that the only LMX coolers around are a mix of prototypes and samples that were sent off to reviewers and testers.
Der8auer concluded the video by musing about the possibility of a truckload of LMX coolers becoming damaged in a road traffic accident, and the calamity that might ensue... We should probably be thankful that never happened, partly because the cooler didn't make it to the mass production phase.
