Cooler Master MasterAir MA624 Stealth Review: Cool, Quiet and Covert

For our CPU cooling tests, we use the same hardware, overclock and configuration for each test to minimize environment variables in testing. This allows for all results across all coolers tested on the platform to be viable as side-by-side examination for direct compare/contrast.

Comparisons are based on data collected from testing performed on our Intel i9-10850k system, including re-visiting many previously covered products which were originally covered on the prior testing platform which pivoted around an i7-5930k (4.20ghz @1.20v).

All data reported here has been collected on the current Intel i9-10850k platform and will be maintained as like-for-like evaluation of ongoing cooling coverage. We’ve recently swapped the taller, Corsair Dominator RGB DIMMs with Corsair Vengeance LPX for lower-profile memory allowing for higher cooler compatibility for testing.

Prime95 v29.4b8 (no AVX) is used for two-hour intervals, one managing fans at 50% PWM and the other at 100% PWM with RPM measurements being taken every 3 seconds and averaged across the duration of each 2-hour capture. Omitting AVX instruction sets allows for accurate, 100% loads at chosen clock speeds, while allowing AVX instructions would provide higher, albeit, unrealistic synthetic CPU loads and excessive heat production, less indicative of real-world use.

This also allows for a greater range CPU coolers to be tested and compared without the need to configure the system differently for smaller coolers which may not handle the excessive thermal loads being generated during testing, while larger coolers might be better equipped to manage heat output produced by the i9-10850k.

While the test platform is quite capable of a 10-core overclock at 5.0Ghz and 1.265v, we were seeing 360mm AIOs struggle to keep core temperatures in check at lower fan speeds, providing insight that the enthusiast-grade i9s need excellent cooling if the goal is overclocking.

HWInfo64 is used for real-time core temperature readout, thermal throttling alerts, motherboard power consumption, CPU speed and logging of data, while a CrystalFontz CFA-633-TMI-KU is used to monitor and later average both ambient room (2 probes) and motherboard voltage regulator heatsink (2 probes).

With these temperature readings collected, CPU Core is defined as an average of all CPU core temperatures, reported once per second for the entirety of the testing run from HWInfo64 data. This value is then taken as an offset difference from the reported ambient room temperature collected from the CFA-633-TMI-KU (also once per second and averaged). CPU PWM is defined by the voltage regulator heatsink direct temperature probe, as an offset different from the same reported ambient room temperature reading for the same CPU Core test (100%, 50%). This helps define a working model of how well the evaluated cooler performs as a process of also cooling nearby hardware also under load, like our overclocked motherboard voltage regulator heatsink.