CPU Coolers: Cooler Master Gemin II M4 review

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Cooler-Master-GeminiII-M4 1Introduction:

Building a media center or other small format PCs from scratch can be a pain, especially if you want to install a reasonably powerful processor due to the lack of space and airflow. Watercooling is certainly out of the question for most setups (who wants a radiator sitting around their living room?) and the best air cooled CPU coolers tend to be fairly hefty.  So it was a pleasant surprise when we discovered that Cooler Master had released the Gemin II M4, a CPU cooler especially deisgned to fit small format cases.


CPU Socket: Intel® LGA1366/1156/1155/775, AMD FM1/AM3+/AM3/AM2+/AM2

Dimension (W / H / D): 137 x 122 x 59mm (5.4 x 4.8 x 2.3 inch)

Weight: 289g (0.64 lb)

Heat Sink Material: 4 Direct Contact Heat Pipes, Aluminum Fins

Heat Sink Dimensions: 120x 118 x 44 mm (4.7 x 4.6 x 1.7 inch)

Heat Sink Weight: 210g (0.46 lb)

Heat Pipes Dimensions: Ø6mm

GeminII M4-accessory

Fan Dimension (W / H / D): 120 x 120 x 15mm (4.7 x 4.7 x 0.6 inch)

Fan Speed: 500 - 1600 RPM (PWM) ± 10%

Fan Airflow: 17.4 - 58.4 CFM ± 10%

Fan Air Pressure: 0.18 - 1.76mm H2O ± 10%

Fan Life Expectancy: 40,000 hrs

Bearing Type: Long Life Sleeve Bearing

Fan Noise Level (dB-A): 8 - 30 dBA

Fan Weight: 79g (0.17 lb)

Connector: 4-Pin

EAN Code: 4719512032930


As can be seen for the specifications list, the Gemin II M4 is desgned to be compatible with all but the latest LGA 2011 CPU sockets. In order to get the best cooling performance, the heatsink is designed so that the four heatpipes are slightly flattened and are held in direct contact with the CPU allwoing for fast heat dissipation.  The heat pipes are effectively standard U shaped pipes laid on their side and these conduct heat away from the heatsink to the radiator which has a large (but slim) fan to effectively dissapate heat.  The fan is spring mounted, making it easy to "upgrade" should the need arise (for most people and indeed purposes this fan would be fine though).

Insstallation, although easy, is a bit of a bugbear if the cooler is to be fitted as an upgrade, as the whole system needs to be disassembled so that the back of the motherboard can be accessed, but for new builds this is obviously easy..  The Gemin II M4 comes with a series of retention plates for fitting (dependent on your socket type), which are fitted onto the cooler and then screwed through the motherboard on to a backplate, which secures the CPU cooler to the CPU..  This way of fixing CPU coolers is far more secure and allows for the correct pressure to be maintained on the CPU, in turn preventing damage when installing.

GeminII M4-06We tested the Cooler Master Gemin II M4 into one of our compact media center PCs on an AM3 socket. As mentioned (and consistent with the majority of higher specification CPU coolers) we had to disassemble the machine before we could install the cooler, but it was simple and straightforward to fit to the motherboard and CPU. Once the machine was rebuilt, we ran consecutive runs on OCCT to fully load the CPU and compared the relative temperatures at idle and under full load against the stock fan.  At idle the temperatures were similar (~2-3°C lower than the stock), however under full load the Gemini M4 II showed a massive improvement (~12°C on average lower than the stock cooler).  It is important to note however that these figures were monitored in a compact multimedia case and that there would be variability from case to case dependent on the airflow design/fan setup and also the CPU installed. Although we could have tested the cooling under overclocking, small factor cases and multimedia cases are not ideal setups for overclocked system due to limited airflow.


~£26 (at the time of writing)


4.5/5 - As a dedicated CPU cooler for a small format/multimedia center case, the Gemin II M4 is ideal, providing enhanced cooling over the stock cooler we compared it against at stock CPU speeds.

PU Socket Intel® LGA1366/1156/1155/775
Dimension (W / H / D) 137 x 122 x 59mm (5.4 x 4.8 x 2.3 inch)
Weight 289g (0.64 lb)
Heat Sink Material 4 Direct Contact Heat Pipes
Aluminum Fins
Heat Sink Dimensions 120x 118 x 44 mm (4.7 x 4.6 x 1.7 inch)
Heat Sink Weight 210g (0.46 lb)
Heat Pipes Dimensions Ø6mm
Fan Dimension (W / H / D) 120 x 120 x 15mm (4.7 x 4.7 x 0.6 inch)
Fan Speed 500 - 1600 RPM (PWM) ± 10%
Fan Airflow 17.4 - 58.4 CFM ± 10%
Fan Air Pressure 0.18 - 1.76mm H2O ± 10%
Fan Life Expectancy 40,000 hrs
Bearing Type Long Life Sleeve Bearing
Fan Noise Level (dB-A) 8 - 30 dBA
Fan Weight 79g (0.17 lb)
Connector 4-Pin
EAN Code 4719512032930