How we test
In autumn 2011, we devised a new testing procedure for computer cases. After trying out different testing configurations, we arrived at a relatively simple yet effective set-up.
Every computer has heat sources that cause the temperature to rise when there is insufficient ventilation. The main heat sources are the CPU and the video card. Depending on the processor, it can easily produce 90 to 100 watts of heat. With new high-end processors this can go all the way up to 130 watts. If you overclock your processor, then the amount of heat produced can be even higher.
The second heat source is the video card. A modern high-end card such as the GeForce GTX 580 has a maximum power usage of 244 watts, and a GTX 590 can use up to 265 watts. A decent processor and video card can therefore easily use 300 to 350 watts, most of which is converted into heat. Add the motherboard, the hard drive, and an optical drive into the mix, and the 400-watt mark isn’t far off.
In order to consistently and reliably be able to reproduce 400 watts of heat emission, we chose to work with two verifiable heat sources of 200 watts each. Two professional 200W light bulbs serve this purpose. With an efficiency of less than 3 percent, a 200W light bulb consistently emits about 195 watts of heat.
Our testing configuration consists of a defective motherboard on which we mounted two fittings- one close to where the CPU would be, the other where normally a video card would be located. By switching on one or two light bulbs we simulate a system that emits almost 200 watts or almost 400 watts, respectively.
We have also mounted a temperature sensor on the motherboard. After the temperature has stabilised, we measure at 200 watts to simulate a mid-range system, and at 400 watts to simulate a high-end system. Both scenarios are done with the case fans that came with the case, once at 7V and once at 12V.
As already mentioned above, we also measure the other side of the cooling coin, namely the amount of noise produced. We do this in a sound-proof box, measuring the noise at a distance of 10 centimetres. This is done without case fans, with the fans operating at 7V and at 12V. The CPU cooler used is a Scythe Mugen 2, the power supply is a Scythe Gouriki 3 700-watt model and lastly an old 80 GB 7200rpm hard disk completes the setup.
The picture below shows the new testing setup: