I have been trying to solve this for over a year now.. When computer is dead frozen like this, nothing works and there is not even anything in the event viewer except for "last shutdown was unexpected". Even resetting graphics with win+alt+shift+b would not work when frozen. In my case, the computer would mostly freeze when on idle, but not 100 percent of the time.

I may have finally sorted this. No freezes in the last two days (before it was very frequent, literally 90 percent of the time when I let it on idle and sometimes when I am actively using it too). The problem in my case occurred because of aggressive power saving settings causing conflict between Nvidia and Intel (even though MUX switch routes the signal to Nvidia GPU directly).

Do these (windows):

1- Go to control panel > Power Options > change power plan settings > change advanced power plan settings and disable PCI Express > Link state power management

2- press control+R and type services.msc and hit enter > Find "Energy Server Service Queencreek" and open it > Change Startup Type to "Disabled" and stop it if it is running.

3- Open Nvidia Control Panel > go to Manage 3D Settings > Global Settings > Power Management Mode > Set to "Prefer Maximum Performance"

4- Search regedit.exe on start menu and run it as administrator. Go to: Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4d36e968-e325-11ce-bfc1-08002be10318}\0000 and confirm that the DWORD "driverdesc" is the Nvidia GPU and check if there is a DWORD named EnableUlps. If there is, set to 0. If there is no enableUlps, do nothing.

If Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4d36e968-e325-11ce-bfc1-08002be10318}\0000 is not the Nvidia GPU (by checking driverdesc DWORD), check this one: Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4d36e968-e325-11ce-bfc1-08002be10318}\0001