I have 3 Vega 56 cards. One MSI and two Sapphire reference cards. I was running them in my gaming PC and everything was working ok. Had two attached to the Motherboard and one on a riser out of the tower, with the side open. They were running fine. Hashing 5700 H/s on Cryptonight with no issues of instability.
I built a rig for these cards so I could get my gaming PC back and have had crazy instability. I am not sure if it has to do with the PCie SSD that I am using in the M2 slot, or that I am using 3 risers now but it keeps crashing. Anyone have any experience with instability and no real solutions to be found? I feel like I have tried everything. I have use Wattman, use OverdriveNtool without wattman but nothing seems to be stable. I just removed that SSD and installed a new version of Windows on a Samsung EVO SSD. Hopefully this works. (Will update later) Maybe windows install was corrupted on the other hard drive. Also, I do not think it has to do with temps, since I have a giant box fan blowing on the cards and have the fans at 3000 or max at times.
Hardware below:
Z170-AR motherboard
https://www.asus.com/us/Motherboards/Z170-AR/
Corsair AW1200i Power Supply
http://www.corsair.com/en-us/ax1200i-digital-atx-power-supply-1200-watt-80-plus-platinum-certified-fully-modular-psu
8 GB of Ram
A PCie wireless card
Risers
HDMI dongle
I have been using Hella's guide on Reddit and Circusdad's guide but nothing is working. I went back to original BIOS, ran DDU a million times it seems but I keep having issues. (Also done the disable driver thing, and using Teamviewer) Do I need to change the PCie lane settings to Gen 1 or Gen 2? Any ideas are appreciated. Any opinions on what it could be? The miner runs for a while an then crashes randomly. Then I see no hashes to the pool and lose my mind. Please help me get my sanity back.
https://www.reddit.com/r/MoneroMining/comments/74hjqn/monero_and_vega_the_definitive_guide/
Btw these above guides are great. Please feel free to share your own experiences and maybe we can help each other.
Update, 28-Dec-17: Make sure you do not use the CPU to mine in the dual miner. I have heard from a few Vega builders that this caused many issues. Unless you have a powerful CPU don't bother, the extra hash from mining with the CPU will just take away from GPU mining.