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Add2PSU : Easily add a second PSU to your system.

For ages, when we start playing with DIY computer we start low of medium ans then increase the number of hardware we own but also the power needed to run a big configuration. Today in the labs is an adapter to plug a second PSU to you system and have it synchronized booted up with the first one.

In the Gaming world, the regular upgrade is mainly for higher clocked CPU, a better VGA or another extra VGA for SLi or Crossfire setup. in the Overclocking world the increse in PSU powerage is mainly due to high overclock or more vga too…

In the end we usually upgrade the mainboard/cpu/vga combo and rely on the PSU, and lately the outcome of the 1000W and 1200W PSU solve most of the problem of power outage and limitationon big builds.

When you upgrade you have then two choice, buy a bigger PSU to feed all the power for your system… or use 2 smaller PSU (mainly two you already have or can have for much cheaper than a big PSU.) and then you need to synchronize both PSU to start at the same time, here come the Add2PSU adapter.


It was possible before with an adapter or by linking the green wire (Pin #16) from one alim to the other one. But all tha possibilities where home made or not reliable over time… especially depending on your soldering /DIY / modding skills.


The Add2PSU adapter is to help you out in that way, it’s an adapter where you plug a cable from the first PSU and the 24/20 pin from the second PSU. That way once you power up your system, the second PSU will follow automatically.

On the technical side, this is compoased by a Green PCB with a 24PIN ATX connector, a regular 4 pin connector and a relay (GB-1C-12L for the electronic fanboys). What is happening is when you power on the first PSU, connected to the 4Pins on the Add2PSU board, the relay is powered (from the 12V line regarding the datasheet of the relay), this then make the contact for the second PSU’s “Power_On” wire located on PIN #16 in the ATX connector.

There is 2 hole that can be used for mouting the adapter in the case but there is also a double-tape on the back to stick it almost anywhere you want.

David Lorentzen is the guy making this idea a real product, the ADD2PSU adapter is available online for 19.95$ + 1.99$ shipping that is a bit high price point, while the alternative at LIAN-LI is about 11-16$ but less easy to use and hide in a case…

As this is the rev. A we hope that next batch of this adapter can be made with a black PCB, and more space between the 24PIn and the 4Pin connector to avoid problem with large 4Pin connector on the PSU that is something bending a bit.

Here is a video demo of how it works :


About Isaïe Trouffman Simonnet

Co-creator, President and Editor-In-chief for OverClocking-TV since 2008, Trouffman is mainly in charge of developing the general OCTV's activites by covering the IT shows like CES and Computex. He reported for OCTV on different live event such as GOOC and MOA being mainly in front of the camera entertaining the viewers. For contact, buzz ideas and other project related to reviews or websites he's the guy!