Cooler Master Nepton 240M Review: The Power of Silence

Test System

Testing Methodology

Test was conducted inside a case for close to real-world performance. An NZXT Switch 810 SE full-tower case was used (supports up to 360mm radiators at the top) and the radiator was mounted at the top with the fans pushing cold air from outside through the radiator. This eliminates performance variance due to warm air from case internal (if the fans are positioned to exhaust up) vs controlled fresh intake air going through the radiator. Ambient temperature is measured at the radiator fan intake and kept constant. Testing was reset when the ambient air rises one degree up or down from the target temperature of 23.5C. To get closer to real world performance, a retail Intel i7-4770K CPU was used (non-delidded). Stock settings use a constant 1.1Vcore voltage while overclock settings use a constant 1.2Vcore voltage. The Intel core i7-4770K integrated graphics was used for display output and no discrete graphics card was installed to prevent additional heat sources from contributing inside and outside the case. Multi-core enhancement is enabled in the BIOS by default and left on (ASUS Turbo Core policy used instead of Intel standard).

Noctua’s NT-H1 thermal compound is used as it is non-conductive, non-corrosive, compressor-cooling compatible, long-term stable in storage or use, and does not require curing time. Plus, the compound’s consistency spreads well under pressure without the need to be manually spread. Line method is used across the i7-4770K surface area and dispersed only by the pressure applied by the IHS-to-coldplate/surface contact.

Mushkin Stealth DDR3 modules ensure full compatibility with any CPU cooler tested as its heatspreaders only add ~1.5mm to the standard JEDEC module height of 30mm compared to other modules which limit cooler compatibility.

Temperatures are averaged (last minute) from individual core temperature results monitored by AIDA64 after 15 minutes using the deafult CPU, FPU, Memory and Cache simultaneous load. AIDA64 is able to use the latest instructions including AVX and AVX2, etc unlike other older CPU load tests so it is also a lot more “future proof” as more software start to utilize it. FPU-only load average is used to simulate worst case scenario load levels similar to Intel Burn Test or OCCT. Please keep in mind that this test is brutal and not even close to real-world load (especially not that constant for that amount of time), so not many CPU coolers are expected to pass this test but the ones that do are exceptional. Results marked “100″ and in red means thermal limit was reached and the CPU was throttled, even for just but a second. This includes results where even just the first core reached the limit and even if it briefly happened. It is marked as 100 in red in the review if it happens three times. Three runs are conducted per cooler and a fourth run is done after a remounting to verify. Last minute average is taken instead of peak because it represents the averaged behaviour of the thermal performance instead of worst-case scenario or a snapshot.

Enermax has generously provided four Enermax 120mm Twister Pressure fans to use for standardised testing. This allows for 240mm radiator testing in push as well as push-pull setups. All benchmarks will be tested at 12V and 7V fan loads, including the bundled fans as well as the Twister Pressure fans. If the fan bundled comes with its own fan controller or presets via hardware or software, those presets will be included as well if different from the 12V and 7V fan speeds.

Enermax Twister Pressure Specifications:

These benchmark results are not directly comparable to any benchmark results previously published due to the nature of the testing procedure using a non-synthetic load.

The Corsair HX850W’s fans only ramp up when system load is past 20% making it an excellent power supply to use for when testing the CPU cooler’s noise levels. Any load under that and the fan does not spin at all, effectively acting in passive mode.

The SPL-8810 meter is placed 51cm from the source fan to measure sound level. The entire test unit sans case are transposed into an open air test bench (DimasTech Mini V1) for the sound testing and moved to an acoustically treated room to get the ambient noise as low as controllably possible for real-world results. All other fans are disabled to eliminate sound sources that are not from the cooling unit itself that is being tested. This includes all case fans and all other component fan is shut off. The boiler during winter or the air conditioner during summer is also shut off to eliminate ambient noise further and sound testing is conducted from 2AM to 5AM so sound traffic from the outside is minimized as much as possible. Fan levels are controlled manually via software and at a separate time from the temperature testing.