I've decided to join the recent trend of mining cryptocoins with GPUs. First, I got a GPU (an EVGA 1070) to complement my 970 and stuck it in my desktop. This is nowhere near profitable because I'd have to block an I7 machine to mine on 2 cards, and also get annoyed because I can't use it. also, rather than my previous attempt few years back using a couple of cards stuck in a desktop PC and having all family complaining of the noise, I've decided to build a proper rig and have them complain even more! :)

Now, when looking at dedicated rigs, I'd needed something which can support 8 cards (or more?). Unfortunately, the running price for the metal frame is about 250Eur. It looks nice TBH, but I'd rather spend it on a GPU :). Enter DIY.

Hardware

Components:

  • 8 L-shaped metal rods 1 meter long, 1.5mm thick, with 1cm each side (4eur/piece)
  • 1 square-shaped rod, 1 meter long, 1mm thick, 1.5cm square side (9eur/piece)
  • many M3 screws (15mm long are OK) (5eur)
  • a Plexiglas sheet (150x100x0.5 cm) (about 15 eur, but I had it lying around). Otherwise, it's probably better to go for an alu piece.
  • M2.5 standoffs (2eur)

Total: approx 65 Eur

Tools:

  • a drilling machine
  • filing tools
  • a Dremmel
  • sandpaper
  • hot glue gun
  • ATX motherboard 1:1 printed on an A3 (optional)

The rig frame shape

I've seen some rigs with complex shapes for the GPU section (likely to save on cost), but I chose to build a parallelipipedic (rectangular bar) variant. This also allowed me to use L-shaped profiles for aluminium bars too.

Designing the base frame

The base frame needs to hold the PSU(s) and the motherboard. Eventually, it might need to also hold a PCI-E 3-4 riser.

PCIE riser

I've seen quite a lot of pics where the mobo was placed flat on the ground/base. Initially, I wanted to create an aluminium flat base for everything, but I had the plexi sheet lying around and I figured I could at least get my motherboard on it. So I:

  • cut a piece a bit larger than the motherboard,
  • marked the holes for ATX screws using the print (frankly, I used the mobo itself because I could not find the print ATM)
  • fixed the standoffs

The finished sheet looks like this:

Motherboard

I've taken this approach to make the rig more transportable. Unfortunately, there are consequences:

  • I'd need some sort of railings on the base frame to hold this in place.
  • I could not use the same approach for the PSU. I'll have to procure some aluminium sheets.

The frame looks like this (sorry, no interim pic):

Base frame

You could probably see I used the hot glue to fix the plexiglass sheet and there's also some padding because I've tried initially to put the motherboard directly on the rails. I figured afterwards the motherboard is too flexible for my comfort and I build the plexiglass plate

A note for the future is: Hot glue is not ideal because now I'll have difficulties to remove the rods.

Some comments

  1. 2m rods are cheaper but more difficult to transport.
  2. In retrospect, I'd now use square-shaped rods for the frame with plastic joints because it's more elegant than having 20+ screws holding the thing together.