Build external power supply for large GPU video cards

Abstract

This article describe a process to build an external power supply using off the self parts available in Amazon that can be turn on with your main computer.

A couple of weeks ago I was considering getting a newer GTX 1080 TI (250w) video for my HP Z800. I have one with a 1100 watts power supply and 2x 6-pin PCI Express power connectors, that are suppose to be on the limit of the capacity. Personally I prefer to have more power headroom for this sort of application to I came up with the idea of using an exg=ternal power supply for the new video card.

I was looking for of an of the shelf PSU, but it seems that since 2006 the market has disappear in favor of larger ATX power supplies. Alas, this wouldn't allow me to reuse my case.

Therefore I decided to build my own solution by picking an ITX/M-ATX case, my choice of power supply, an ATX power relay and some Molex 4-PIN and PCI-Express 8 pin extension cables (Amazon). The following is a list of the parts:

1x Golden Field N+1 (21) ITX/M-ATX case, [1]
1x Corsair CX Series 750 Watt 80 Plus Bronze Certified Modular Power Supply, [2]
1x Multiple Power Supply Adapter and Daisy Chain Connector Add2PSU by Genetek Electric, [3]
1x Accessbuy 180-Piece Rubber Grommet Shop Assortment, [4]
2x CRJ 4-Pin Molex Male to Female Extension Black Sleeved 24" Cable, [5]
2x Phanteks 8 to 8 (6+2) Pin PCI-Express Premium Sleeved Extension Cable, [6]

The following are some pictures that describe the building process: