Koolance CPU-LN2 Liquid Nitrogen EvaporatorFri, Jul 03, 2009 - 12:00 AM
Liquid Nitrogen Benching Results
Unlike dry ice which requires a solvent bath to function properly, liquid nitrogen can be simply poured. This means that the tall acetal extension on the CPU-LN2 was not necessary so I removed it. This greatly eased the amount of condensation issues I had as I no longer had the extension condensing water between the acetal and the insulation and subsequently dripping down the tube and freezing around the mount. Unlike dry ice pots which typically have thin bases with modest amounts of surface area, a proper liquid nitrogen pot has a thick base and extensive amounts of surface area. The perfect liquid nitrogen pot has a thick enough base to reduce temperature swing between idle and load and sufficient amounts of surface area so that lots of heat can be removed quickly to combat heavy loads as seen in 3DMark 2006 or Vantage, and wPrime 1024M.
Using a Fluke 16 for the IHS and the UEI DT150 for the container temp.
So what.. No results? How best to put this.. the CPU-LN2 is not an adequate liquid nitrogen pot. I started my testing on AMD’s Phenom II X4 955 and even with the pot full of nitrogen I was still seeing massive(20C+) swings in base temperature through the relatively short 3D06. For example I can run 3DMark 2006 at 5900MHz on my F1EE but I had to drop down to 5650MHz with the CPU-LN2 due to the processor getting too warm through the CPU test and crashing. wPrime 1024M crashed at 5800MHz typically between 65 and 80 seconds.
With Core i7 the pot performed even worse. Unlike Phenom II, Core i7 has a coldbug so I thought couldn’t run the pot full of nitrogen. I started with a container base temperature of -90 Celsius and the CPU at 5.1GHz with 1.5vcore. On the F1EE I would typically see through the 06 CPU test the base temperature to drop to around -87C to -88C depending on how evenly I poured the liquid nitrogen. On the CPU-LN2 though base temperatures would plummet down to -65 Celsius and only recover once the benchmark was complete. Perplexed I pulled the base temperature down to -90 Celsius again, filled the pot all the way up with liquid nitrogen, and tried again. Once again the base temperatures plummeted to around -70 Celsius. If the pot, full of nitrogen, can’t hold the CPU at only 5.1GHz through 06, I was worried what would happen through wPrime 1024M.
Starting at -90 Celsius and the pot full of nitrogen I fired up wPrime 1024M at 5.1GHz. The CPU remained stable for 55 to 60 seconds before base temperatures hit -50 Celsius and the system blue-screened. I tried every trick I knew, remounted the pot, poured a little water into the base to boost surface area, and various pouring techniques but all to no avail. The CPU-LN2 just isn’t an adequate liquid nitrogen pot.