CRYPTOCURRENCY MINING GPU's Not Showing on Asus Motherboards! FIXED!

Hi guys, thanks for taking the time to read this short blog post! As I was recently setting up another mining rig on an Asus H270 motherboard running Windows I came across a fix that worked for me with some GPU issues so I thought I would share it.

Most common rig building problem seems to be the graphics cards or GPU's not being recognised or a number of them not appearing. This I believe, aside from possible hardware issues such as a lack of PSU power or faulty hardware (risers probably), is predominantly a BIOS issue.

My setup is currently as follows:
4 x Powercolor Red Devil RX570 4GB
1 x Asus H270-Plus Motherboard
1 x 8GB DDR4 Ram 2133
1 x 120GB SSD
1 x Intel Pentium G4400 Processor
1 x EVGA G3 850W Supernova PSU
4 x Version 7 Sata Riser Cables
Windows 7 SP1 x64

I intend to add another 850W power supply and 4 more AMD GPU's to take the total up to 8 cards. So far I have the 4 card rig running stable at around 90MH/s on Nicehash Miner with stock settings (no GPU Bios mods or overclocks as yet).

The issue that some people seem to be having and the one major issue I encountered was GPU's not displaying or the rig not recognizing the graphics cards once they were added. Windows seemed fine with 3 running at one time but would not boot after a fourth was added. I kept on uninstalling and reinstalling the drivers but to no avail. The max was 3 cards showing in Device Manager.

I did a little bit of Googling to try and find a solution and it turns out this was due to my BIOS settings being incorrect. I suspected it may have been a lack of power but the EVGA 850W I am using has 4 GPU rails and should run the cards no problem. It was the first time I have used an Asus motherboard, my previous build was on an MSI Gaming Plus.

It turns out that the BIOS settings were to blame. After fiddling about with them and many reboots, I finally found a configuration that worked.

You have to go into the BIOS menu (Advanced Setup):
Click on the advanced tab and go to System Agent (SA) Configuration.
Go to DMI Configuration and change DMI Max Link Speed to Gen 2
Go to PEG Port Configuration and set both PCIEX speeds to Gen 2 (Leave Spectrum Clocking as Auto)
Go to PCH Configuration > PCIe Configuration and Set PCIe Speed to Gen 2
Enable Above 4G Encoding to get the cards to display (location of this setting varies on different motherboards).

That should be it. Plug in all your cards and off you go. Windows or your other OS should recognise all the cards attached to your board. Bear in mind Windows will only recognize a maximum of 8 cards total, whereas Linus will do more.

I found this video on YouTube from Angry Chicken that takes you through the process. Thanks Angry Chicken!