How We Test

Coolers are tested using Intel Core i5 2500K loaded LinX AVX Edition software, temperatures are taken wih RealTemp, which shows DTS (Digital Thermal Sensor) data. Coolers are tested 3 times using different CPU overclock settings or until critical temperature is reached (usually when testing low-end coolers). We use the following overclock settings for i5 2500K: 3.7 GHz @ 1.22V, 4.2 GHz @1.3V and  4.5 GHz @ 1.35V. We take away room temperature and calculate the average maximum temperature of all four cores.

Testbed:
CPU: Intel Core i5 2500K
MB: Gigabyte Z68A-D3
RAM: Patriot 2x4GB DDR3 1600MHz 9-9-9-24-1
SSD: Samsung 830 256GB
VGA: MSI GeForce GTX 460 768MB Cyclone
PSU: Seasonic S12II-620 Bronze
Case: Silverstone Redline RL01 SST-RL01

Two fans are installed inside our test system case. In front we have a stock SilverStone Redline RL01 intake 120 mm fan running at  about 1400 RPM and in the back one Xilence 120 mm fan running at 1500 RPM.

Along with Scythe Ashura we also include performance results of these coolers:

Deepcool Ice Blade Pro V2.0

Prolimatech Megahalems Rev. C (with Red Vortex 12 LED)

Prolimatech Panther

SilverStone Argon AR01 (review)

Zalman CNPS11X Performa

We test some of the coolers two times - one with fan running at maximum speed (at 12 V voltage) and second with fan running with PWM control, connected to motherboard. If only one result is shown, it means fan is running at full speed.