Test System & Temperature Results

Test System

Testing Procedure

All testing is done at a room temperature of 23°C (73°F), with a 1°C margin of error. The coolers are tested with Turbo, EIST, and C1E enabled, which will allow the CPU to clock down to a low 1.6 GHz while idle, or clock up to proper speeds under stock and overclocked conditions. The retail Intel Core i7-4770K I use for testing at stock is set to load-optimized defaults with the CPU's voltage at a static 1.15 V. Overclocked, the processor is running at 4.2 GHz on the CPU and 3.9 GHz on cache, with respective voltages set to 1.20 V and 1.15 V. During all these tests, fans are set to run at 100% in the BIOS, with temperatures being recorded by AIDA64.

The idle test will consist of the CPU sitting idle at the desktop for 15 minutes. This will allow for a stable temperature reading that will be recorded at the end of those 15 minutes.

Wprime's and AIDA64's CPU test represent typical multi-threaded loads. Both offer consistent results, with one being a benchmarking application and the other a stability test. Both are run for 15 minutes before the peak reading during the test is recorded and taken as the result. This test lets enthusiasts know what temperatures they can expect to see with games and applications. Wprime is set to eight threads while AIDA64 is configured to stress the CPU, FPU, cache, and system memory.

AIDA64 offers maximum heat generation when set to stress just the FPU in the stability test, which will really push the CPU. This test represents extreme loads much like LinX, Prime95, and other extreme stress tests many users are familiar with.

Idle Temperatures

After letting the system sit at idle for awhile, we see Scythe's Mugen 4 perform as expected. While it sets no records for idle temperatures, it does manage to easily keep up with the competition.

Typical Load Temperatures

In Wprime, we see the Mugen 4 fall back at stock, tying the much smaller and cheaper Raijintek Aidos. Once the system is overclocked, however, things change. At 68°C, the Scythe cooler manages to place itself smack dab in the middle of the competition, just 1°C behind Raijintek's Ereboss and in a tie with Noctua's NH-U12S.


Firing up Aida64's CPU benchmark, the Scythe Mugen 4 performs rather well at stock. Moving up a few spots, it manages to tie its more expensive competitors, including be quiet!'s Shadow Rock 2. The cooler maintains its middle-of-the-pack performance with the CPU overlock; however, it falls behind Noctua's far more expensive NH-U12S by 1°C. So far, the Scythe Mugen 4 is performing rather well in comparison to its competition.

Max Load Temperatures

Now for the torture test. Using Aida 64 to stress the CPU's FPU for maximum heatload, the Scythe Mugen 4 manages to keep its cool. Again, stock performance, while not terrible, leaves something to be desired. However, with a recorded temperature of 91°C, the Mugen 4 again climbs the charts to tie multiple coolers once the CPU has been overlocked. While it fails to stand out in terms of raw performance, it does manage to impress considering its price at the time of writing is $45.99.