an idiot question - eatx12v
 

okay please explain why there is 4 and 8 pins for eatx12v (cpu to psu connector)


i used 4 pin and no problem for 2 years... but i wonder why 8 pin was there... so i want to make sure...



i use i7 920 so it uses 130watts at 100% td...

Because certain CPU's require that Power when maxed to there full potential. Simple as that.

My Board won't boot if I have a 4pin plugged in.

-ST

It just depends on the board design. Realistically the 4 pin can supply enough power for a CPU, but the 8 pin COULD supply more power if it was required. It would reduce the amperage being drawn through the each wire to allow for a more clean power if you had a very high power draw.

okay thats clear... and make a sense... but the real question is... how do i know if i need 4 or 8 pins? ;\

a motherboard with a 4 pin slot needs a 4 pin, and a motherboard with an 8 pin will always work with an 8 pin, but will sometimes work with only a 4 pin (depends on the motherboard). As far as I know there aren't any CPU that require an 8 pin, they just have them for better OCing (atleast that's my understanding).

I'm not an electrical engineer so don't know the exact spec, but I'd hazard a guess that using the 8 pin connector allows for the 12V CPU current draw to be split between the two plugs. I've seen what drawing a lot of power through a single 12V motherboard pin can do when folding with 4 GPUs and it's not pretty. :)

There's definitely no cut and dry guide to what works and what doesn't on an 8 pin board. I have a 350W cheapo PSU that I tried using to power up my Sabertooth for the first time. It has a 4 pin and the board refused to boot. With an Antec 450W PSU, also 4 pin, the board powered up no issue.

http://www.hardwarecanucks.com/forum...connector.html

here you go :) alot of these connectors just add extra ground pins with a "sence" circuit of some kind on the part in question. I have used 8 pin pci-e as 6 pins as an exmaple by letting the 2 extra pins "hang" without an issue. But yeh, sometimes things do not always work as one wants, all things are not built the same way of course(though there is specs, alot of makers do not always follow them as they should example-80 plus certification)

hmm i should search in mobo area... i did search in psu only...


oh btw... i use 8pin and i saw 2% boost on cpu ( from 3.06 to 3.3 on occt)... i dont overclock it yet... o_O?