Playing a movie from PC on TV, external HDD vs HDMI picture quality aka grain

[andrein]

Since i can't properly play HDR movies from my PC to TV, i thought i should give it a try by playing straight from an external HDD. Not only that i got a HDR signal but the overall picture quality improved. I'm not talking about HDR vs SDR but how clear and sharp the picture was. There was no noise, no grain or anything like that. If i play a 1080p, 4k non HDR or anything else from my computer, i get that grain which bothers me but not when played from HDD. I'm trying to understand what's going on.
It only happens for movies and not games. I've tried multiple media players but still the same.
My PC : i5 4670k, GTX 1080Ti, Windows 10 and what i think, a good 2.0 3m HDMI cable.
TV : LG C7V 65"
The resolution set is 3,840x2,160 @23Hz because the TV doesn't like 60Hz for movies and it stutters.
I've read somewhere about the TV overscanning on hdmi or something like that. I guess it has to do with the way the signal is carried through HDMI or that it may be over processed.
I'd hate to have to copy everything on my HDD and play on my TV so maybe there is a fix out there.
Thank you!

 

[rustigsmed]

what mode is your tv in? -make sure no interpolation is set, and your in game mode or pc or similar.

what players have you used? have you tried Media Player Classic or the new VLC (version 3.0)? https://www.videolan.org/vlc/download-windows.html

your system should be able to play 4k absolutely fine. im betting its the media player. also check what your nVidia control panel settings are. Movies are naturally set in YCbCr colour mode and not rgb which may also help.

good luck

 

[andrein]

TV is in HDMI mode. Whether is set to this or PC mode, image quality it's the same and i loose some of the options.
Yes, i did try those media players. nVidia is set to "Let application decide". Haven't played with those options.

 

[rustigsmed]

that version has been only out for 10 days - so im just making sure it is the new one, it fixed stutter issues on 10bit 4k files.
are you saying it works ok on the pc if you set it to 23hz (and not 60hz) or does it stutter in both?

also this is from rtings.com

"All the common input resolutions are supported. For the TV to properly display 4:4:4 color, the HDMI input in use must have its icon changed to 'PC'. To play 4k @ 60 Hz @ 4:2:2 or 4:4:4 color, 'HDMI ULTRA HD Deep Color' in the general settings must be enabled for the input being used."

 

[andrein]

It's not about the stutter as that was fixed by switching to 23Hz. My issue is with the image quality and the grain that appears when watching from PC.