I built a mining rig using an ASRock Q1900M mini combo motherboard with CPU. This motherboard has a passive cooler and uses very little power so I chose it for the mining rig build.
This board has three PCIe slots and all I needed for this rig was two slots. Since I am installing two GTX 1080 Ti graphics cards which use 250 Watts each, I am not going to be putting any more cards on this rig anyway.
I was talking about installing my old GT 770 graphics card on this rig as well but decided that it would burn too much power combined with the two 1080s.
I used the dogfish 30 GB SSD hard drive I recently received in the mail along with some used RAM I had laying around. An 850 Watt Thermaltake power supply was to power the rig.
I first build a mining rig frame out of lumber and then put the motherboard and power supply in place. Then I wired everything up and got the hard drive connected.
Next I installed Windows 10 Pro from a USB stick and then did all the current Windows updates.
During the entire process I used the original onboard graphics card for the installation.
Then I put on the first graphics card with its riser and started the computer. I installed the proper drivers and then mined a bit with the card to make sure it was running well.
And finally I installed the second graphics card and got the rig mining.
These are the parts I used:
ASRock mini motherboard and CPU: http://amzn.to/2C5Rd6F
Dogfish 30 GB SSD Hard Drive: http://amzn.to/2EQFv2V
Thermaltake 850 Watt power supply: http://amzn.to/2ES02nO
EVGA GeForce GTX 1080Ti graphics cards: http://amzn.to/2C81uPR