Test System and 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, Noctua's NH-L9x65 places dead last, which is not surprising after all because the cooler is a small form-factor design with a 92 mm x 92 mm x 14 mm fan.

Typical Load Temperatures

The Noctua NH-L9x65 comes in dead last in the first load test. It falls behind another small form-factor cooler, the Reeven Steropes, by 4°C at stock. With the CPU overclocked, Noctua's cooler falls even further back, winding up 6°C behind the Steropes.


Firing up Aida64's CPU benchmark, which increases the load, Noctua's NH-L9x65 again brings up the rear. At stock, it falls 3°C behind the Steropes. With the system overclocked, the NH-L9x65 falls behind by 9°C. It certainly won't be winning any awards for performance.

Max Load Temperatures

Now for the torture test. Using Aida 64 to maximize heat by loading the CPU's FPU, we see the NH-L9x65 again bring up the rear, this time by a rather large margin at stock, and the CPU thermal throttled with the overclock. At this point, the last result was unavoidable considering the cooler's diminutive size. It really is meant for CPUs with a low TDP.