New GPU stability issues

[Gameymammal]

After some research and discussion on the forum, I recently uograded from an r9 390 to a Vega 56. It's a great card, but I've been having some stability issues ever since installing. I have overclocked the card, but the issues happen even if I have everything on the preset balanced options. There are 2 kinds of crashes which have been occuring:

1. The screen freezes, then goes black, then turns on again like nothing happens. This always results in the Radeon settings app crashing as well (not sure really if this is a cause or sympton). Sometimes this recurrs very soon after, sometimes a few minutes later, but it never goes away until I restart the PC. 
2. The whole system crashes. This is most likely a result of the overclocked, but I'll include it anyway because it has been pretty unpredictable. I'll find a stable overclock, play a game for a few hours sometimes, and then when I turn my PC on again the next day it crashes. I can get the system back to the overclock, but it takes the usual process of incrementally getting there and usually a few restarts. 

The bottom line is I can't keep having to tweak settings and restart several time every time I want to turn on my computer. I've tried driver rollbacks and updates and pulling out and reinstalling the card without fixing the issue. I thought it may be a power thing but I am undervolting the card as well so I don't really see that as an issue. Build details below and any tips would be much appreciated!

• Intel - Core i7-4790 3.6GHz Quad-Core
• PowerColor RED DRAGON Radeon RX Vega 56 
• Gigabyte - GA-H97M-D3H Micro ATX LGA1150 Motherboard
• 4x4GB G.Skill - Ripjaws X Series DDR3-2133
• Raidmax - Vampire 800W 80+ Gold Certified Semi-Modular ATX Power Supply
• Samsung - 850 EVO-Series 250GB 2.5" Solid State Drive
• Western Digital - Caviar Blue 1TB 3.5" 7200RPM Internal Hard Drive

[Crunchy Dragon]

What are you using to overclock?

 

I would use MSI Afterburner over anything preset.

[Gameymammal]

1 hour ago, Crunchy Dragon said:

What are you using to overclock?

 

I would use MSI Afterburner over anything preset.

I've been using WattMan in the Radeon settings (when it decides not to crash).

[Gameymammal]

Just in case anyone comes across this in their own research for a similar issue, I've managed to mostly resolve the issue by increasing the TDR from 2 to 8 per the steps here. It's definitely a band-aid rather than a fix, but I have been able to game without issues for several days in a row now without issue.