Even I has the same question. searched forums a bit.
There are a lot of factors that serves as a base for selecting great overclockable motherboards from poor ones:
- The number of power phases it possess. More phases mean more power stability and a stable overclock.
- Overall quality of individual components. Cheap capacitors will blow up faster and endure less heat than better ones.
- Great overclock ability. Since it needs to exceed specifications, it has to use larger heatsinks, offer a great range of adjustable voltages and clocks.
- A complete features list. Overclocking a board that lacks many features could be a pain in the ass while another board having the complete stuff could make your life way easier and achieve better performance.
- Heat uniformity and dissipation. Both are important as heat uniformity assures us that the motherboard works efficiently and that no specific component will blow up first. Also better heat dissipation will make the board last years longer. For example mine Gigabyte GA-965P-DS3 rev3.3 motherboard is said to be able to last 20 years!! And it's technology has been improved even more on recent boards.
- The brand is important too! Cause some motherboards makers do have lots of experience building overclockable war machines and some does have experience doing the minimum so that it passes certain certifications. You see the difference.
Boards made for overclock are more expensive, but will last longer and oftentimes comes with lots of features, and support the latest technologies so that it will really serve a long time if well maintained.
The quality of the motherboard is as good as the weakest component it uses. Imagine a chain: The whole is as good as the weakest link.