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

At idle, the Enermax ETS-T40 Black Twiser is rather impressive, staying near the top of the charts. With the CPU overlocked, it even managed to tie the Phanteks PH-TC12DX, which uses two fans.

Typical Load Temperatures

The ETS-T40 Black Twister does well in our first load test, placing in the top five at stock, where it manages to tie far costlier solutions. When the system is overclocked, the cooler slips back a few spots, falling behind the more richly featured Scythe Ashura. It does, however, manage to beat out the more expensive Noctua NH-U12S.


Pushing a heavier workload with AIDA64's CPU stability test shows the ETS-T40 Black Twister to again do well at both stock and overclocked. It manages to either tie or beat the Scythe Ashura, Noctua NH-U12S, or Silverstone Argon AR03, for example.

Max Load Temperatures

Using AIDA64's FPU stability test to push CPU load levels to the maximum, it becomes clear that the ETS-T40 Black Twister can get the job done. Coming in at 75°C at stock and 91°C when the system is overclocked, it performs similarly to Scythe's Ashura CPU cooler. The only issue is that the Enermax cooler does not offer the same memory clearance. What it does offer is far more visual flair, although which of the two is more important will come down to the user's preference. In terms of overall performance, the ETS-T40 Black Twister has proven to be very competitive for its price.