Hey there Oberon,
I can understand the frustration of having a beefy system like you have yet still having Diablo 3 performing as if the system is barely able to run the game. There is one known issue that may explain game freezes that’s related to the latest versions of Windows. It may be a factor here, yet I also have a couple other ideas to suggest.
First is to make sure the game is using the more powerful GTX 2080 Super, as laptops with Windows will sometimes get confused and try to use the Intel UHD graphics instead. We can force this with adjusting 2 settings:
3D settings
- Right click on the desktop and open the Nvidia Control Panel
- Click on Manage 3D Settings on the left
- Go to the Program Settings Tab
- Browse and select the Blizzard game. If there is a drop-down menu called Select Preferred Graphics Processor, choose High Performance Nvidia Processor. This drop-down may not always be present
- Click Add and close the Control Panel
PhysX physics engine
- Right click on the desktop and open the Nvidia Control Panel
- Click on Configure Surround PhysX on the left
- On the PhysX Settings drop-down select the Nvidia card
- Click Apply and close the Control Panel
- Restart the computer after configuring the options in Nvidia Control Panel
The other idea is to see if just resetting the in-game settings as well as video driver helps.
If neither of the above works, check out this thread for the known issue. There are a few ideas there from other players that have helped that may be worth trying since this does sound similar.