S3220DGF, Nvidia GTX 970, HDR Problem

UPDATE：

Using HDMI cable can do 144Hz HDR. But the DP cable that comes with the monitor is DP 1.2. I think that's why it doesn't run HDR on DP cable. But this monitor only supports 165Hz through DP cable. Come on Dell, you can do better than that.

There appears to be some confusion about the S3220DGF and what it supports. The S3220DGF was marketed as an AMD FreeSync 2 monitor to be used with AMD FreeSync video cards. Using an AMD FreeSync video card in AMD FreeSync mode, the S3220DGF supports =
HDMI 48Hz to 144Hz
DP 48Hz to 164Hz

The online S3220DGF User's Guide shows on multiple pages that HDMI 2.0 supports 144Hz and DP 1.4 supports 164Hz.

Page 8 - Smooth, low latency HDR gaming with AMD FreeSync Premium Pro Technology.

All that to say that we have no idea how the AMD FreeSync 2 S3220DGF will act when using your 2014 released Nvidia GTX 970.

Dell HDR is a two step process. You have to change both the Windows 10 Display setting and in the monitor Menu OSD (On Screen Display).

When using the Windows desktop or any other non-HDR content like Windows Explorer, YouTube, etc., HDR should be Off
* Change the S3220DGF OSD- Display- Smart HDR to Off
* Right click on Windows 10 Display Settings
* Switch HDR and advanced colors to Off

When using an HDR Game or Movie, HDR should be On
* Change the S3220DGF OSD- Display- Smart HDR to either Game HDR or Movie HDR
* Right click on Windows 10 Display Settings
* Switch HDR and advanced colors to On

Thanks for the reply. My problem is simple:

HDMI 1440P at 144Hz, --------  HDR is working Fine.

2014 GTX 970 DP1.4,  HBR3 Cable, 1440P, 165HZ ------  NO HDR, the HDR option is grey out in windows option and games.

Display Devices
---------------
Card name: NVIDIA GeForce GTX 970
Manufacturer: NVIDIA
Chip type: GeForce GTX 970
DAC type: Integrated RAMDAC
Device Type: Full Device (POST)
Device Key: Enum\PCI\VEN_10DE&DEV_13C2&SUBSYS_29743842&REV_A1
Device Status: 0180200A [DN_DRIVER_LOADED|DN_STARTED|DN_DISABLEABLE|DN_NT_ENUMERATOR|DN_NT_DRIVER]
Device Problem Code: No Problem
Driver Problem Code: Unknown
Display Memory: 12208 MB
Dedicated Memory: 4043 MB
Shared Memory: 8164 MB
Current Mode: 2560 x 1440 (32 bit) (165Hz)

HDR Support: Not Supported

Display Topology: Internal
Display Color Space: DXGI_COLOR_SPACE_RGB_FULL_G22_NONE_P709
Color Primaries: Red(0.675781,0.314453), Green(0.272461,0.657227), Blue(0.151367,0.068359), White Point(0.313477,0.329102)
Display Luminance: Min Luminance = 0.154200, Max Luminance = 518.753479, MaxFullFrameLuminance = 518.753479
Monitor Name: Dell S3220DGF(DisplayPort)
Monitor Model: DELL S3220DGF
Monitor Id: DELD0F4
Native Mode: 2560 x 1440(p) (59.951Hz)
Output Type: Displayport External
Monitor Capabilities: HDR Supported (BT2020RGB BT2020YCC Eotf2084Supported )
Display Pixel Format: DISPLAYCONFIG_PIXELFORMAT_32BPP
Advanced Color: Not Supported

I had the same problem with my 2014 980 GTX. It's the display port input on the card, not the monitor or the cable. Our old cards have the older ports that don't support HDR.

Thank you for that, my 1070TI had a similar problem where all of a sudden HDR stopped working. I figured it was the updated nVidia drivers but once I switched the Display Port on my 1070TI to another one HDR worked fine again.