Cooler Master GeminII S524 CPU Cooler Review

Product: Cooler Master GeminII S524 CPU Cooler
Company: Cooler Master
Author: James Prior
Editor: Charles Oliver
Date: January 23rd, 2012

Performance Testing

Our testing was performed on the following system:

Test Setup

The system specifications are below:

Component Specification
Mainboard ASUS RoG Rampage III GENE
Processor Core i7 920 2.66GHz
Graphics Card AMD Radeon HD 6450
Memory 2x2GB Mushkin Blackline
Audio Creative X-Fi MB 2
PSU Corsair HX650
Case Open Bench
Storage WD Raptor 80GB + Seagate 7200.11 500GB
Heatsink/Fan Intel Stock Cooler
  Cooler Master GeminII S524
Display Dell P2210H
Operating System Windows 7 64-bit Ultimate SP1
Driver Catalyst 12.1 Preview

The GeminII S524 should offer better cooling for both the processor and the system components as it moves air over more area. The stock Intel design does move some air across neighboring CPU components but the fan is much smaller than the Cooler Master supplied fan. The GeminII S524 is rated for all modern CPUs except Sandy Bridge-E, but that seems to be more because of socket compatibility (the GeminII S524 was launched before SB-E's X79 platform) than heat load capacity.

Heatsink base contact area

For our testing we compared idle and load temperatures of four sensors, as seen by ASUS' RoG Connect feature. We monitored the Core i7 920's CPU core and IOH temperatures, as well as the mainboard temperature sensor. An additional temperature sensor was placed behind the mainboard under the socket, connected to the OPT input on the mainboard. Fan control is disabled, running the cooler fans at full speed.

ASUS RoG Connect

Stock CPU Clock Temperatures

After recording values at idle, we used Prime95 (in place FFT, custom 4096K size) torture test for 45 minutes to act as a heat load, and recorded the new values. The process was repeated for Intel stock cooler and GeminII S524. Additionally, we swapped out the 120mm fan for a 140mm, as found in Cooler Master HAF cases. This fan is a lower RPM fan, which should offer quieter operation for similar cooling potential.

140mm Fan


Prime95 (custom - in place fft torture test, 4096K size) was run for 45 minutes as a heat load test. Temperatures are degrees C.

Sensor   Intel Stock HSF GeminII S524 GeminII S524 140
CPU Idle 37 34 34
  Load 80 58 62
IOH Idle 49 44 52
  Load 55 51 61
MB Idle 28 28 29
  Load 32 29 29
OPT Idle 33 30 33
  Load 55 40 46

As you can see, the Intel stock cooler gets pretty hot under stock load. Moving to the GeminII S524 gives a decrease in CPU core load temperature of 22 degrees with the stock fan, and 18 degrees with the 140mm low rpm fan. The 140mm fan doesn't cool the IOH as well as the stock cooler, an interesting observation. The OPT temperatures are both significantly lower with either fan on the GeminII, suggesting more cooling is being applied to surface around the socket, and the mainboard temperature is lower, too.

Component Clearance

Next we overclocked the Intel Core i7 920 to 3.5GHz, using 175MHz bClk and 1755MHz RAM. This required increasing voltages, 1.418v vCore, 1.65v vDIMM, 1.31v vIOH, 1.4v QPI/VTT. Given the high load temperature seen with the stock cooler we didn't feel comfortable using it with these settings, instead only testing the GeminII S524 with the two fan configurations.

Sensor   GeminII S524 GeminII S524 140
CPU Idle 44 47
  Load 75 84
IOH Idle 52 62
  Load 61 79
MB Idle 29 29
  Load 29 30
OPT Idle 35 38
  Load 49 58

The higher RPM and higher airflow of the 120mm stock fan offers better cooling for this configuration, albeit more noisily. The 140mm fan still keeps thermals under control - just. For overclocking, a different 140mm fan would be preferable than this admittedly different purpose designed case fan. The stock 120mm included with the GeminII S524 allows the overclocked configuration to run cooler than stock with the Intel cooler, with the exception of the IOH - understandable, given the big increase in voltage to the DIMMs and controller to run at 1755MHz.