Help needed: dual 8-pin CPU connector

[zombie67]

Edit: Never mind. It turns out that I had a second 8-pin cable extender in my cable bin, and my PSU has two 8-pin cables. So I just hooked up both.

I have a machine with an MSI Big Bang Marshal (B3). I have to replace the PSU (I'll tell you why later). Anyway, it has dual 8-pin connectors for the CPU. However it does not need to have both fed, and I had only one 8-pin cable going from the PSU to the connectors. Like a dumb-ass, I did not look at how it was plugged in before taking off the old one. Now I need to hook up the new PSU, and I can't figure out how to do this. The 8-pin connector is split in two plugs of 4. So, do I do this:

XX__ | XX__

Or this:

XXXX | ____

Or this:

____ | XXXX

??

For some reason, I *think* it was hooked up the first way. I seem to recall that half of each connector was covered with stickers. But I can't find anything in the documentation about this. I tried searching the web, but none of the reviews show the board actually hooked up in a system, or talk about the need to use both (or not). I think I even asked about this here during the original install, but can't find that either! Ugh. HELP!

[John P. Myers]

I also have a Big Bang Marshal, and as hard as i tried too remember how i was supposed to go, i can't :p Like you, i plugged in both of the 8-pins. I remember the stickers too, but can't remember their positions. The only thing left to go by is when using a 4-pin the shape of the ends of the plug will only go in 1 way. Just spent 30 mins looking for something about it online and can't find a single word or picture :/

[zombie67]

Heh. Thanks for looking anyway!

[Duke of Buckingham]

http://peterwalters64.files.wordpress.com/2012/01/looking.jpg

http://2.bp.blogspot.com/-H7bqjkelicI/Tw99FkI2rLI/AAAAAAAAfn8/9j_thAhrI9A/s1600/blob-looking-for-something-clipart.gif

http://www.tracetheplace.co.uk/images/home_found_it.jpg

[rgathright]

IMPRESSIVE MOTHERBOARD!

I am not surprised that zombie67 is the one who using such state-of-the-art hardware. You continue to amaze me with your ability to build machines. :cool:

http://www.msi.com/product/mb/Big-Bang-Marshal--B3-.html#/?div=Basic (http://www.msi.com/product/mb/Big-Bang-Marshal--B3-.html#/?div=Basic)

http://tbreak.com/tech/files/IMG_0691-21.jpg

[zombie67]

Hey Z, just for future reference... a split 8-pin connector (dual 4-pin) uses polarized connectors. So for a MB with an 8-pin socket, each half of the dual 4-pin will only fit on one side of the socket. On a MB with a 4-pin socket then either one of the dual 4-pins will work. This scheme is part of the ATX specification for backward compatibility.

Right. But with two 8 pin sockets, you have four different possibilities, for how you could possible connect that split 8-pin cable. So my first illustration was off. Here are the four:

XX__ | __XX
__XX | XX__
XXXX | ____
____ | XXXX

[Fire$torm]

Right. But with two 8 pin sockets, you have four different possibilities, for how you could possible connect that split 8-pin cable. So my first illustration was off. Here are the four:

XX__ | __XX
__XX | XX__
XXXX | ____
____ | XXXX

Right, that is way I deleted my post.... :P

In all honesty I do not think it matters. I rummaged through a few of the review sites and no mention of "Warnings" and such about the dual 8-pin sockets so I believe the two sockets are wired in parallel. The second socket is for Extreme Overclocking.

Edit: ---> http://www.vortez.net/articles_pages/msi_big_bang_marshal_review,3.html



With a 24-Phase Power Design this motherboard is designed for extreme overclocking hence the reason we also have dual 8-pin power – providing more than 60A for more stability and lower impedance.

So dual 8-pin sockets wired in parallel will allow for the 60 Amps of current. DAMN that is an awful lot of power...!!!

[John P. Myers]

I'm with F$ on this. Pretty sure the 2 8-pins are wired in parallel, so you could use either XXXX | ____ or XX__ | __XX and it'll work properly. I had used both 8-pins because i had planned on "extreme overclocking" though now my MSI Big Bang Marshal is in a storage unit in Arkansas, so i can't test out either of those configurations :/ Since you have both 8-pins plugged in, try unplugging the bottom one and reboot. It's a quick test to make sure it'll still work just fine.

[kmanley57]

You are very close! The power connectors are rated for 1-2 amps each, so if you are not pulling LOTS of current
due to over-clocking your processor real hard, you only need to use one of the connectors. (AKA the connector gets hot and MELTS!)

You could run it for a while(hour) then feel the 8-pin power connector, and if it feels warm then you need the other 8-pin connector also.
Splitting the connector pins spreads the heat between the two connectors if you want to. But you are looking at the current draw on the pins,
and splitting the 8-pin does not fix that.

[John P. Myers]

You are very close! The power connectors are rated for 1-2 amps each, so if you are not pulling LOTS of current
due to over-clocking your processor real hard, you only need to use one of the connectors. (AKA the connector gets hot and MELTS!)

You could run it for a while(hour) then feel the 8-pin power connector, and if it feels warm then you need the other 8-pin connector also.
Splitting the connector pins spreads the heat between the two connectors if you want to. But you are looking at the current draw on the pins,
and splitting the 8-pin does not fix that.

Actually i'm thinking it would be better to split it into 2 4-pins, assuming no (or very little) overclocking. The reason is because of the 24 phase VRM. They are divided into banks and i'm almost certain if there's no power going to the 2nd 8-pin connector, then not all of the banks can be used, which would limit you to either 12 or even 6 effective phases.

The little details are starting to come back to me :p