Yeah, I'm not trying to purposefully put you on HDMI 2.1 as some kind of 'low standard' ... because ... on balance ... you can probably get more out of it than DP1.4 ... in general.
However, since you mentioned that your GFX card is not upgraded, then DP1.4 will likely be your best bet for a fuller flavour.
Just ... ... when you do upgrade that ... don't prop up the NVidia machine. ;-) ... They hold back technology (LIKE DP2.whatever or HDMI2.1) which literally holds you back when you do something like the exact thing that you have done, here. They only just made ALL their ports 'modern' in the latest generation of cards. This matters when you decide that you want to plug your PC into your lovely, huge, 4K telly, AVR, or projector, to game on. ;-)
Oh, and if you want to get into splitters, using HDMI for sound only, and all that stuff ... ... then ... let's get the whiskey out and discuss how Windows is an utter shit show ... and how to use one or two splitters, and which ones don't fuck your shit up even more! 😅