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, the Kelvin S24 does okay at stock clocks. However, with the CPU overclocked, it does much better by placing a mere 2°C behind the lead, Swiftech's H240-X.

Typical Load Temperatures

In Wprime, the first typical load test, Fractal Design's Kelvin S24 proves itself a solid contender by performing as well as the Enermax LIQTECH 240 and only placing 1-2°C behind the Corsair H105.


Similar to the Wprime results, the Aida64's CPU benchmark has the Fractal Design Kelvin S24 place just 2°C behind the Corsair H105 at both stock and overclocked settings. It, once again, ties the Enermax LIQTECH 240.

Max Load Temperatures

Now for the torture test. Using Aida 64 to produce as much heat as possible by putting a load on the CPU's FPU, the Kelvin S24 ends up 3°C behind the Corsair H105 and 1°C behind the Enermax LIQTECH 240 at stock. Overclocking the CPU, however, has the Kelvin S24 gain ground as it closes the gap to the Corsair H105 and beats the Enermax LIQTECH 240. Overall, a solid showing by Fractal Design's first all-in-one expandable liquid CPU cooler.