Enable 4K UHD (3840x2160) on Mac Mini 2012 and 2014 in Windows via DisplayPort

Enable UHD (3840x2160@30Hz) external with HD 4000 via DisplayPort

Windows 8.1

MacMini 2012 (MD387LL/A) (should work on all other models from 2012 and 2014)

ASUS PB279Q via DisplayPort
Driver: 10.18.10.3958 (30-Sep-14)

Intel HD Graphics Control Panel

1. Right Click on Desktop - Graphic Options / Custom Resolutions

2. Choose Yes

3. Fill in: Width: 3840, Height: 2160, Refresh Rate: 30, Timing Standard: CVT-RB

4. Click on the Plus button - bottom-right

5. Choose yes for the warning message.

6. The new resolution should appear in the Custom Resolutions List.

7. Right Click on Desktop - Screen Resolution

8. Select the newly added resolution from the list.

9. Enjoy

The only downsize is that it is at 30Hz - not good for games and fast dragging windows 🙂