some extreme CPU or GPU would consume lots power, and with 8pin connector, the terminal might not be able to support such high current flow, and would over-heated. To avoid such risk, MB has two ways:
1. adding more 4 / 6 / 8 pin connector on MB/VGA cards: this is the common way
2. using one 10 / 12 pin connector: this way is rarely seem, yet save more space
who knows in the near future, would the 10 / 12 pin connector on MB / VGA card be more common. Yet we can seem more PSU manufacturers follow ENERMAX way to benefit the space saving advantage.