I have now implemented 4K for all my video on my HTPC. I changed those settings I needed to to match what you described in your post Jmone:
https://yabb.jriver.com/interact/index.php?topic=115543.msg803243#msg803243What I have different is:
1. I'm using a presentation queue of 8 frames rather than 4. Why 4?
2. When I set up 3D in the nVidia Control Panel I only had the options of 8 or 12 bit, so selected 12 bit. I don't have HDR content, and haven't turned on HDR & WCG (Wide Colour Gamut) in Windows 10 yet, but plan to try that as my TV can handle it. I assume that my TV is telling the nVidia driver that it is capable of 12 bit colour, and that is will use 10 bit if that is what the source provides.... But now I check again it is back to 8 bit colour. Hmmm. Maybe I had HDR turned on in Windows and/or on the TV when I ran the wizard.
3. I have the Windows 10 Custom Scaling Option set to 200% so that MC is readable on the TV from 3.5 metres away. This doubled the default font from 9 to 18 points, which was too big, so I dropped it back to 14 points, which works fine. Options > Tree & View > Advanced > Select font.
4. I have set the "Media Center 24.exe" to use the "High DPI Scaling Override" to "Application".
Things I noticed, and questions.
a. To play 3D content i do indeed need to play the main movie title only. 3D doesn't work when the Blu-ray menu is activated. In fact the menu doesn't work either, showing a message "3D EXPERIENCE REQUIRES 3D ENABLED TV & PLAYER" after a short display of a black screen. Will 3D blu-ray menus ever be possible?
b. When playing 3D content madVR does report D3D11 is being used, even though I don't have it turned on in madVR. 2D content uses D3D9.
c. The madVR Statistics display is also shown in 3D. Surprise!
d. MY TV does indeed switch to 1080p when 3D content is detected. As there are no user settings to make this happen, I assume that switching is built into the MC 3D functionality. Or is the nVidia driver doing the switching?
e. As I have the Windows 10 scaling set to 200%. when 3D is playing in 1080p instead of 4K the top drop-down OSD display is double size. But still usable. The font size might be contributing to that also.
So basically it all works with the settings recommended.
No need to change madVR settings to do the Display Resolution changes. MC is doing it all. Note that I didn't reset madVR before testing 3D, I just change the settings as required. I am using Jinc for both Chroma and Up/Down scaling. As per my signature, I'm using a NVidia MSI GeForce GTX 1060 GAMING X, 6GB card with the latest drivers, 397.93.
Now what happens if I turn on HDR in Windows and on the TV...