4 + 4 cpu connector does not seem to fit the ATX12V 8-pin connector

G

Guest

Guest
I have an Asus Sabertooth 990FX R2.0 and the HCG-750M 4 + 4 cpu power connector.
It turns out that the pins don't match. I thought that both cpu cables should connect in
each part of the connector to the ATX12V 8 pin. Could I use a power supply with an
8 Pin EPS 12V connector such as the TP-750 Blue? Maybe I have another hardware
version of the power supply?...
 
Solution
When did I ever say that?

What I'm saying is that there's no need to use the modular cable that has the 8-pin EPS12V connector on it.

G

Guest

Guest
I went ahead and bought a HCG-850M power supply which has an EPS 12V 8-pin connector.
To the best of my knowledge, this is the ATX12V 8-pin connector. I just tested my system
with the TP-750 New Blue power supply with the same kind of connector and I was able to
install windows. I just wish I understood why the 4 + 4 cpu connector does not have the
same pin layout as the motherboard. Would It be ok to connect both 4 + 4 connectors,
even if they don't match? Why would the connectors not match anyway?
 

King Kevain

Reputable
Dec 10, 2014
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As per ATX specifications, they should have fit - you must have had the sockets rotated the wrong way or you somehow got a PSU with non ATX leads. I know some of the Corsair ones are a bit crap..maybe they were built by the same crappy OEM..
 
psu_rear_closea_small.jpg

Antec HCG-850M +12V power Distribution:

+12V1:
• SATA modular power cables
• Molex Peripheral modular power cables
• Left 16-pin modular panel socket

+12V2:
• (4+4)-pin ATX12V/EPS12V hardwired CPU power cable
• ATX (20+4)-pin main Motherboard hardwired power cable
• Right 16-pin modular panel socket

One or both PCI-E power cables, if used, should be connected to the left 16-pin modular panel socket on +12V1.

The modular EPS12V power cable, if used, should be connected to the right 16-pin modular panel socket on +12V2.

This is the preferred cable connection configuration that should prevent any power distribution problems.

The fact that half of the (4+4)-pin ATX12V/EPS12V hardwired CPU power cable's connector pins don't exactly match the motherboard's 8-pin CPU power socket doesn't matter since it has been designed to work this way. It is keyed such that it will only fit in one way. A D-shaped pin housing will always fit into a square-shaped socket hole but a square-shaped pin housing will not fit into a D-shaped socket hole.
 
G

Guest

Guest
Are you saying that I wouldn't use any one of the 5-pin sockets from
the top for any of the SATA or Molex connectors but the left 16-pin
socket? Also, for the +12V2 rail, there aren't any modular cables
available, for the (4 + 4)-pin ATX12V/EPS12V cpu or ATX (20+4) pin
connectors so I'm assuming that you mean that I just use the
hardwired cables. Here is what I've considered so far...

Hardwired Cables
(4 + 4)-pin ATX/EPS12V cpu power cable (I'll use the EPS12V 8 pin connector)
ATX (20 + 4)-pin main motherboard power cable

Modular Socket Cables
+12V1 top 5-pin sockets
SATA
Molex

+12V1 bottom left 16-pin sockets
PCI-E

+12V2 bottom right 16-pin sockets
EPS12V 8 pin power cable

What is the difference between using the (4 + 4)-pin ATX/EPS12V
cpu connector and the EPS12V 8 pin connector? Why do the
(4 + 4)-pin ATX/EPS12V cpu connector pins not match, In all of
my experience, the pins always match. Why does the (4 + 4)-pin
ATX/EPS12V cpu connectors even exists? Is it because some
motherboards only have an ATX12V 4-pin connector?
 
When did I ever say that?

What I'm saying is that there's no need to use the modular cable that has the 8-pin EPS12V connector on it.


The (4+4)-pin CPU power connector doesn't need to match the solid 8-pin CPU power connector. Only half of it needs to match. As long as the keying prevents incorrect insertion there's nothing to worry about. The connector only supplies +12V (yellow colored wires) and ground (black colored wires). Compare the color of the wires and their orientation with respect to the latch between the (4+4)-pin and the 8-pin connectors. The yellow colored wires should be on the same side (i.e. the side with the latch) and the black wires on the opposite side.

The EPS12V 8-pin connector is on the left and the (4+4)-pin connector is on the right in the following image (from Silverstone Zeus 1200W PSU):
ZM1200-33.jpg
You can see that the right half of the (4+4)-pin connector in the image doesn't match the equivalent pins on the EPS12V 8-pin connector. It doesn't need to.
 
Solution