How We Tested

We tested different positions for the case fan using a Core i5-2500K, which is a quad-core CPU with a 3.3 GHz clock and a TDP of 95 W. This CPU was overclocked to 4.5 GHz (increasing the multiplier to 45x), with a core voltage (Vcore) of 1.1 V. The video card used was a Point of View GeForce GTX 460 with its stock cooler.

We used a Thermalright True Spirit 120 CPU cooler with the thermal compound that comes with it.

We utilized the Cooler Master Elite 430 case, which has the power supply at the bottom, and has the possibility of installing case fans at the rear, top, front, side and bottom panels. We didn’t test the fan at the bottom panel because the power supply blocked it.

The fan used in the case is the SilverStone FM123. We chose this fan because it is very strong. It was always used at its maximum speed of 2,700 rpm. On tests with two fans, the FM123 was on the rear panel, whereas we installed a Deepcool Wind Blade 120 mm fan (1,300 rpm) at the front or side panels.

We tested the effect of the case fan on the temperatures in different configurations. First, we tested with no case fan and the left panel open. Then we tested with no fan and the case closed. The following tests were done with the case fan at the rear, top, side, and front panels. Finally, we ran a test with one fan at the rear and another one at the front panel, and then one at the rear and another one at the side panel.

Figure 1 shows our system with the rear and front fans installed.

Which is the best place to install a case fan?Figure 1: Test system

Room temperature measurements were taken with a digital thermometer. The core temperature was read with the SpeedFan program (available from the CPU thermal sensors), using an arithmetic average of the core temperature readings. GPU temperature was also measured with SpeedFan.

The temperatures of the chipset, hard disk and memory modules were read using the NZXT SENTRY 2 fan controller, which has five thermometers.

During all of the tests, both CPU and GPU were under full load by running the Prime95 program in the "In-place large FFTs" mode and the [email protected] GPU3 client simultaneously.

Hardware Configuration

Operating System Configuration

  • Windows 7 Home Premium 64-bit SP1
  • NTFS Filesystem

Software Used

Error Margin

Since both room temperature and core temperature readings have 1°C resolution, we adopted a 2°C error margin, meaning temperature differences below 2°C are considered irrelevant.

Rafael Otto Coelho is a physicist with a master's degree in Education, and is a college professor in Brazil.