Arctic Freezer Xtreme Rev 2 Heatsink Review

The Arctic Freezer Xtreme Rev 2 is designed for Intel Socket LGA 1366 / 1156 / 1155 / 775 and Athlon 64 processors using a combination of the included hardware and stock mounting brackets.  Here is an overview of the system and testing methodology.

Asus P8Z68 Deluze Gen3 Intel Z68 Chipset
Intel Core i7 2600K (3.5Ghz) Quad Core 4 x 256KB L2 Cache 8MB L3 Cache
Arctic Freezer Xtreme Rev 2
Cooler Master X6 Elite

The CPUID System Monitor was used to obtain and record system temperature data and being that this is a quad core processor we need something that will work across all of the cores at once.  For this task we're using a new version of Prime95 (p95v255a) that will allow you to spawn (n) instances to test with.

Editors note: Even though the Windows 7 task manager reported 100% processor usage we could never attain a 100% of the rated heat output as documented by Intel (see above) when using Prime95 as a basis for that heat production. Knowing this we ran the stress test until the maximum temperature was attainted and stabilized.

Other things to consider when judging software induced heat output.
a) Clock throttling by the processor at high temperatures.
b) Normal software isn't designed to produce maximum heat output.
c) Variances of cooling temperature.
d) Variances in CPU load.
e) Inaccuracies in thermal diode readouts.
Of course the list goes on..

Our testing methodology is aimed to provide a real world look into this heatsink given the test system provided.

A C/W rating can quickly be calculated using this formula.

C/W = (CPU temp - Ambient temp)/(Variance(%) * CPU Watts)
Allowed variance for this test = 85%
CPU Watts = 95W

0.27 C/W = (43C - 21C)/(.85(95W))

For this next test the CPU speed was cranked up to 4.4Ghz and the test was re-run.

To calculate a new C/W rating for this test we will need to factor in the increased processor wattage. The formula and constants for this are listed below.

ocC/W = dCPU Watts * (ocMhz / dMhz) * (ocVcore / dVcore)2
ocMhz = 4400
dMhz = 3500
ocVcore = 1.31
dVcore = 1.2
The variance still applies for our C/W calculation
Allowed variance for this test = 85%
CPU Watts = 142W

0.33 C/W = (62C - 22C)/(.85(142W))

In our heatsink and waterblock tests we don't really focus on overall load temperatures but rather how well the product can remove heat given a specified heat load. Since this is a real world testing method we need to take into consideration real world variables and estimate tolerances. This is why we normally only apply 85% of the total wattage output to our heat calculations.

The resulting C/W number is used to rate how efficient a heatsink or waterblock is based on the given heat load. These numbers can be used to determine heat capacity, the larger the difference the less efficient the heatsink is. (aka not good for overclocking)

Arctic claims the Freezer Xtreme Rev2 is designed for power users which would indicate to us that a certain degree of overclocking may be involved.  For this test we choose to only apply a mild overclock and see how the heatsink reacted.  Much to our surprise the Freezer Xtreme started to get saturated at 4.4Ghz which we calculated was around 142w of heat.  
 
In these tests you'll notice that the C/W numbers had a radical change between the default and overclocked tests.  This would indicate that the Freezer Xtreme has reached its saturation capacity and is starting to have difficulty dissipating the load.  Given the 62c load temp we would be a little worried about running this overclock for any length of time without a better fan.
 
Keep in mind these calculations are provided for demonstration purposes only and may not reflect the actual lab tested C/W rating, but we're pretty close.