After reading countless topics about this error I kinda fixed it for me.
First off : I'm running the latest drivers, updates and whatever, keeping my rig as optimized as I can (since it's part of my job anyways).
The error is difficult to track down when you can't look at what the game is actually REALLY doing codewise but after a while I found something that happend everytime right before a crash : The GPU temperature went up pretty fast from around 40°C / 104°F to 80°C / 176 °F. Fast...like in about 3-4 minutes! Shortly after that the game usually went unstable and crashed with the device hung error. Sooo :
- The GPU temperature went to pretty much exactly 80°C (176 °F). On my GeForce 760 that's usually not anything to worry about tho it's quite high.
- People who claimed to have fixed their error underclocked their GPUs. Well surely that usually leads to less heat.
- Running in windows borderless for whatever reason seems to also generalte less heat (75°C / 167°F).
After figuring it MIGHT have to do something related to a heat issue I just set the GPU fans to 80% (instead of the usual 30-40%) cooling the card down to stable 75°C / 167°F when playing DA3. So far, no crash even with one long six hour session. I then reversed the test, setting the GPU to "automatic fancontrol", waited until it was down to 40°C / 104°C and started the game :
- Temperatures went up high nearly instantly. While loading a save in Redcliffe (usually a lot of geometry and tesselation going on), it crashed nearly instantly.
- I tried again. Again in Redcliffe...it took a while longer. Maybe half an hour. Again crash.
So I needed to verify. Same savefile, location, settings. Just set the fanspeed to 80%. Four hours of playtime later...nothing. No crash. No stutter. No nothing to worry about.
Whatever caused the crash for me seems to be gone with lower GPU temperatures.
The odd thing here is that even tho the GPU was getting hot as hell in automatic settings, it didn't bother to turn up the fanspeed on it's own like it usually would do at that point. Other games (please insert name of first person shooter here) do that. I know since I tested that too and I could clearly see a change in fanspeed there. Just no changes in DA3 at all. So whatever is going on it seems to be some engine related thing that dosn't work well with the drivers, letting the GPU overheat and therefore "hang".
So yeah...concluding that long wall of text here : Try cooling your graphics cards even if they USUALLY work just fine (if nothing else, open your PCs case, turn up your fan speed with whatever software you like and so on). There might be a bigger issue here.