Why can´t I change to 12 bpc bit depth?

[mikaelmark]

have an Asus GeForce GTX 970 OC 4GB with latest driver 8.1.880.0, and I have in the Nvidia Control panel set the resolution to 4k x2k, 3840 x 2160 and frequency to 60Hz and YCbCr444 (connected to my Samsung 4K with UHD-color activated and HDMI 2.0.

But after reinstalling Windows 10, I can´t change the bit depth from 8 bpc and limit dynamic space. Do anyone know why I can´t choose 12 bpc and full dynamic space? It was possible before reinstalling Windows.


/ Mikael

 

[sxr7171]

Try setting RGB.

 

[mikaelmark]

Try setting RGB.

I have tried RGB, but it will not work either.

And I really want to go with Chroma 444 because I use UHD color at my Samsung 4K TV.

But when I lower the resulotion to 1920 x 1080, then I can change to 12 bpc. But when I then go back to 3840 x 2160, it can´t be chosen again. So now I have nothing choosed, it´s just blank! May that be a problem?

I attaching a screen dump (the display language is in swedish)

https://onedrive.live.com/redir?res...authkey=!AAbJ-LPi4h8E5_0&v=3&ithint=photo,jpg

 

[neviir]

So now I have nothing choosed, it´s just blank! May that be a problem?

As strange as it sounds, it may be the cable. AFAIK you need a powered cable (or a very, very short one) to handle the bandwidth for 4k HDR. Also, you need to have HDCP 2.0 configured to be able to use 4k HDR for most devices (yay DRM...)

 

[mikaelmark]

Thank´s for your reply, neviir!

I have now replaced the HDMI 1.4 cable with a 2.0 4K, 2 - 3 times the cost and also cleaned the HDMI port at the graphics card with isopranol alcohol. But it´s still the same, the bit depth can not be higher than 8 bpc - but at least at least I will not get any black screens for a few seconds as I get earlier several times/day.

 

[jamexman]

What's your Tv's model?

Sent from my Nexus 6 using Tapatalk

 

[mikaelmark]

UE55JS8005 (Samsung 4K 55")