[SOLVED] Extreme flickering while PC gaming with 4K TV

[irredeemable]

I've replaced my old GTX 750 Ti SC with a RX 580 8GB XXX so I could become a member os the master race again. A couple months ago, I purchased a Samsung 58MU6100 television too (58MU6120 here in Brazil). Never had any issue with the TV (but I think I've never even tried to play anything through the PC since I've beem gaming mostly on PS4 these days). Everything has been working just fine (PS4, streaming throughs apps, remux HDR movies through external device, cable box etc). The videocard is connected to a Dell P2417H monitor too through display port. Connecting the PC to it, there are no issues... until I try to play any game.The screen starts flickering like crazy (sometimes, the PC freezes too - or at least I can't manage to close the game / change the screen back to the monitor). Here are everything that I've already tried so far:

• 
  ■ Replaced the HDMI cables for spares and even bought a new one (2.0, 4K@60Hz). Problem persists.
  ■ Connected the videocard to the monitor through HDMI. No problem at all.
  ■ Connected the videocard to the my old Samsung full HD TV through HDMI. No problem at all.
  ■ Messed with Color Depth (it should be 8 bpc, right?), Pixel Format (4:4:4 if the HDMI por is labeled as PC), GPU Scaling, Scaling Mode and HDCP through Radeon Settings. Problem persists.
  ■ Tried all 3 of the TV's HDMI ports. Problem persists.
  ■ Turned UHD Color off for the respective HDMI port. Problem persists.
  ■ Powered everything up with only the TV connected to the PC. Problem persists.
  ■ Changed the frequency 59 Hz and 30 Hz. Problem persists.

There's probably more, but can't remember it right now. What's odd is that I've already managed to play just fine a few times. Even HDR worked. Can't figure out if it's just a configuration problem or if it's the TV or the GPU.

Edit: It seems to be working with YCbCr 4:2:0.

 

[irredeemable]

The cables I have only support YCbCr 4:2:0. It's working just fine now that I set it properly. Will try to buy a HDMI cable that supports RGB 4:4:4 4K@60Hz, but it's hard to find one here in Brazil - probably gonna have to import it; accepting suggestions.

 

[niktsak77]

The cables I have only support YCbCr 4:2:0. It's working just fine now that I set it properly. Will try to buy a HDMI cable that supports RGB 4:4:4 4K@60Hz, but it's hard to find one here in Brazil - probably gonna have to import it; accepting suggestions.

Hi my friend, i have the same problem, i used the xbox one x cable which is hdmi 2.0 but no luck. Did you find a cable that worked?