A lot of the APU's use 100W. And if you get an unlocked model and intend on overclocking you will likely use even more than 100W.
Ah. I didn't realize the APUs used that amout of wattage. That would explain it, then. Thank you. But that raises another question...
100W divided by 12V = 8.33A
Even a tiny #20 AWG conductor is rated at 11A for chassis wiring: http://www.powerstream.com/Wire_Size.htm
And most power supplies use much larger wire size than that for their CPU power cables. Add to that, the fact that the std 4 pin socket has 2 pair of these. Doubling that number as in the example I showed would seem to be overkill. Not that I'm complaining about getting the extra capacity... just curious.
My Gigabyte manuals say that a 4 pin CPU plug can be used for a CPU with up to a 140 watt TDP.
Everybody went to an 8 pin connector when the P4 EE chips arrived and never went back.
It's like the "+4" part of the main power plug. There's an extra 3.3, 5, 12 volt, and ground wire. You do not really need it to carry extra current to the motherboard any more. The two heaviest power users (CPU and GPU) now have their own individual 12 volt power plugs greatly reducing the amount of power the main power plug needs to handle.
think of more like having a normal cpu and gpu card combo. the better cards require a second power source to be plugged directly into the card. This is an extension of that idea but you cant very well plug that connection directly into the apu. you would have no place to put the heat sink. this is the next step. An 8 pin connection.