For mini-ITX cases we use a different test method than we would for bigger cases. The reason for this is that the test setup for bigger cases does not fit in the mostly very small mini-ITX cases. Therefore, we have tried and tested many different set ups in the past; our current test platform is both very effective as well as very consistent.
As is well known, every computer contains heat sources that cause the temperature in the case to rise when the case does not feature adequate ventilation options. The largest sources of heat in a powerful PC are the processor and the graphics card. Depending on the type, a processor can easily produce 90 to 100 watt of heat and with new high-end processors this can even go up to 130 watt. When overclocking a processor, this can increase even further.
The second major source of heat is the graphics card. A modern high-end card can easily use 250 watt, while models that feature two GPUs can use even more than that. A reasonable processor and graphics card combined can therefore easily use 300 to 350 watt of energy, of which nearly everything is converted to heat. Add to that the power draw of the motherboard, hard disk as well as the optical drive and the total quickly approaches 400 watt.
However, in Mini-ITX cases a heat release of 400 watt is seldom a good idea; you will probably be using a less extreme system. Because of this we made a set up for these tests that is capable of generating a maximum heat of 200 watt. When cross testing this, it turned out to matter very little for the temperature in the case, as long as there is some form of airflow. This is also due to the fact that our test set up is equipped with active cooling in the form of very flat, quiet fans. In the end, the choice for the heat source fell upon power resistors of 50 watt. There are four of these in our test setup, two on a mini-ITX motherboard and two on an insertion card based on a sizable graphics card.
By activating one or two resistors we simulate a system that has a total heat production of 50, 100 or 200 watt. This is done in two steps. First we measure 50 and 100 watt with only the motherboard, followed by 50 watt on the motherboard and 50 watt on the graphics card for 100 watt in total; lastly 100 watt on both. In theory it is possible to test more variations, but the testing simply takes too long in this case: we tried to make a sensible choice. The advantage of this approach and choice is that we can test both flat mini-ITX-cases without room for a graphics card as well as bigger models that do have room for this. Hereby we are able to compare these cases with each other as well.
On the aforementioned motherboard we also installed a temperature sensor that allows us to measure the temperature inside the case. After letting the temperature stabilize, we measure this at a load of 50 watt in order to simulate an entry level system (for example an HTPC), 50+50 watt for a system with a separate graphics card, 100 watt for a powerful compact system and 100+100 watt in order to mimic a high-end system. We measure 50 watt with the fans at 7 volt, as well as 50+50 watt; 100 watt and 100+100 watt are measured with the fans at 12 volt. All measured temperatures are normalized on an ambient temperature of 20 degrees. Aside from that we also measure the temperature with separate temperature sensors positioned on the GPU and CPU, directly on the resistors.
You can see the test setup at work in the pictures below:
We test the noise levels in a soundproof box, in which we can detect all noise above 17 dB(A). Just to be clear: standard ambient noise is about 30 dB(A). In the case we install the test setup as pictured above for cooling performance. We use an old Hitachi Deskstar 7K160 80GB hard drive if the case has room for a 3.5” model; if not we use a Seagate Momentus 5400.6 320GB. We test each case without the case fans running, in order to test the sound dampening ability of the case itself. Additionally, we test the noise levels when the case fans are running at low speed (7V) and high speed (12V).