20-pin ATX + Supermicro PJ1 port?

altano

Active Member
Sep 3, 2011
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Cambridge, MA
Hey Everyone,

The new Epyc Supermicro boards come with this weird power setup: they have both an 8-pin CPU plug and a weird, proprietary-looking port (PJ1) that comes with an ATX adapter (CBL-PWEX-1063). I believe the Xeon D-2100 boards have the same setup:


The manual says:
1.6 Power Supply

As with all computer products, a stable power source is necessary for proper and reliable operation. It is even more important for processors that have high CPU clock rates. It is strongly recommended that you use a high quality power supply that meets ATX power supply Specification 2.02 or above. It must also be SSI compliant. (For more information, please refer to the website at Industry Reference | SNIA). Additionally, in areas where noisy power transmission is present, you may choose to install a line filter to shield the computer from noise. It is recommended that you also install a power surge protector to help avoid problems caused by power surges.

Note: The M11SDV-4C/4CT/8C/8CT/8C+-LN4F motherboard supports either 12V DC in power input or ATX power input. The 12V DC IN power input requires an 8-pin 12V DC IN connection to the JPV1 header. ATX power input requires an 8-pin 12V connections to JPV1 header and PJ1 a 4-pin power connector of an ATX power supply by power cable (24-pin ATX to 4-pin power cable for PJ1, Supermicro P/N: CBL-PWEX-1063). PJ1 allows motherboard control of the 5VStby, power on, power good, and ground signals from the ATX power supply.
Question: Can I use a 20-pin ATX cable (like that found on the PWS-203-1H PSU) with this adapter for the PJ1 port? Like so:
 

altano

Active Member
Sep 3, 2011
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Cambridge, MA
I found no information, said screw it, and have been running the board with the power hooked up as pictured above. Nothing has exploded yet.
 

s0lid

Active Member
Feb 25, 2013
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Tampere, Finland
Seems to provide ground lead, +5V standby, PS_ON and PWR_GOOD signals from/for normal ATX powersupply. Yes you can use 20-pin connectors as those signals are in same places with both 20- and 24-pin atx connectors.
 
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modernist

New Member
Aug 28, 2013
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On a related note, does anyone know what type of connector is used for the PJ1 port, i.e. the small end of the CBL-PWEX-1063 adapter cable? Thinking of upgrading to an Epyc 3000 series motherboard and would prefer to make a custom cable rather than using the adapter.
 

sagra

New Member
Apr 27, 2020
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On a related note, does anyone know what type of connector is used for the PJ1 port
I believe its the Samtec Mini Mate series. IPD1-02-D-K for the connector and CC79R-2024-01-L for the crimps. I haven't tried this yet (just ordered parts) but the pictures look right and the dimensions match.