CoolerMaster Atmos 240 Review

The MasterLiquid Atmos 240 is 240 class AIO liquid cooler, designed to be eco-friendly and customisable. It uses Cooler Masters signature dual chamber pump design and represents the best of modern AIO liquid cooling. The Atmos 240 is priced at $134.99 in the US and £129.99 in the UK.


CPU SocketLGA1700, LGA1200, LGA1151, LGA1150, LGA1155, LGA1156, AM5, AM4
Radiator MaterialAluminium
Radiator Dimensions277 x 119.6 x 27.2mm
Pump Dimensions84.9 x 81 x 53.15mm
Pump Noise Level12 dBA (max)
Pump Connector4pin (PWM)
Pump Power Consumption3.84W
Fan Dimensions (L x W x H)120 x 120 x 25 mm / 4.7 x 4.7 x 1 inch
Fan Quantity2 PCS
Fan Speed690-2500 RPM ± 10%
Fan Airflow70.7 CFM (max)
Fan Noise Level27.2 dBA (max)
Fan Pressure3.61 mmH₂O (max)
Fan Bearing TypeLoop Dynamic Bearing
Fan MTTF>160,000 Hours
Fan Power Connector4pin (PWM)
Fan Rated Voltage12 VDC
Fan Rated Current0.2A
Fan Safety Current0.3A
RAM ClearanceN/A
Warranty5 years
Cooler TypeLiquid Cooler
Radiator Size240


The box is well organised and probably one of the most thought out packaging we’ve seen. If nothing else, is a nice touch.


The includes fans are on quieter side of AIOs we used. This allows the fans to operate at higher RPM, while maintaining the same noise levels.


The CPU pump block measures 53mm in height and around 43mm with cap removed, making it a very solid choice for ITX cases. The pump cover is customisable via 3D-printing. This is cool feature, but we feel few will take advantage, due to no / limited access to 3D printing. The pump noise was fairly restrained, even at 100% speed, atleast on our own unit. It was however audible within roughly 1m in silent environment. At 70%, you’d have have your ear directly to the pump to hear the faint noise. We have however heard some mixed reports on pump behaviour. On final note, the pump has polling issue, meaning the speed readout is incorrectly reported by 3x. CoolerMaster is yet to address this. Thankfully it has no impact on performance.


While we tried to explore CoolerMaster’s MasterCTRL software. Sadly, the v1.0 public software release wouldn’t launch on either of our AM5 systems. This has now been addressed as of software version 1.3. We played around with lightning effects and feel like RGB element of the software and whole box setup requirements bit convoluted. That said, we are not experienced with ARGB software so could be completely normal experience.


Testing is carried out on BC1 (open testbench), using the following hardware, in 20°C ambient room temperature. We noise normalised the fan speeds to 35dB(A) at distance of 50cm. This helps eliminate brute force cooling from higher RPM fans.

CASEBC1 (Open Testbench)
MOTHERBOARDMSI B650M Mortar WiFi (paid link)
CPUR9 7900X (paid link)
CPU COOLERMasterLiquid Atmos 240
GPUGigabyte RX 6900XT Gaming OC (paid link)
RAM32GB TeamGroup Vulcan DDR5, 6000MHz, CL38 (paid link)
PSU SilverStone SX1000R (paid link)


We use Cinebench R23 multicore (stability test), for period of 30 minutes. This provides worse case scenario for a given CPU. CPU coolers are tested across range of CPU’s for data validation and to reduce risk of errors. This also helps account for variables between CPU platforms.


The MasterLiquid Atmos 240 is one of the best 240 AIOs currently available, both in terms of thermal performance and noise levels. It is particularly useful for Mini-ITX builds.

Performance Unnecessary extras that increase AIO pricing, including customisable pump block, ARGB snd MasterCTRL hub.
Pump height (53mm), roughly 43mm with cap removed.Only available with RGB.
4pin PWM controlled pump.Fan splitter is low quality and very stiff.
Quiet pump, even at full speed.
Textured radiator surface finish.