For idle testing, the system was booted up and allowed to stabilize at ~0% CPU usage. Temperature readings were then taken for 10 minutes using RealTemp GT. Prime95 was then used to load the CPU to 100% for another 10 minutes of temperature readings. The cooler was tested on Intel Core i5-2500k and i5-3570k chipsets. The i5-2500k was set to a default clock speed of 3.3GHz and an overclocked speed of 3.8GHz. The i5-3570k was set to a default clock speed of 3.4GHz and overclocked speeds of 3.8GHz and 4.4GHz. Automatic voltage settings were applied for both chipsets. The single temperature recorded was the average between the four cores. Power management features SpeedStep and C1E were disabled to prevent any downclocking during idle testing.
Idle performance of the cooler was as expected, but it comes as a bit of a surprise to see the Deepcool Assassin climb into the mid 50s under a mild overclock. The Cooler Master TPC 812 and Arctic Freezer i30 continue to astound us with their air-cooling capabilities, and it comes as no surprise that a 240mm radiator like the Seidon 240 would run a few degrees cooler. Still, I would have expected more from this cooler given the numbers on the paper and the quality of the materials.
Our Ivy Bridge testing charts are by no means comprehensive at this point, as we have only tested one other CPU cooler on this platform, the Phanteks PH-TC12DX. Keeping in mind that the Phanteks cooler has a single stack of fins compared to the Assassin's two, I am again surprised to see a rather small discrepancy between temps. The dual-tower configuration of the Assassin does manage to provide an extra 2 degrees of overhead under 100% load, but I would have expected a far more impressive price to performance ratio from this large of a cooler. It is worth pointing out that both fans were whisper quiet with the system under full load. They better be, considering the amount of effort Deepcool put into isolating them from the heatsink. If low noise and reliability are high priorities, then you can expect some very good longevity and consistently quiet operation from these fans.