Freesync/VRR - what are the pre-requisites?

kenny saunders · 19 Nov 2021 at 21:22

I have a:

50” QN94A Neo QLED, 120hz VRR (premium freesync) capable monitor (TV), has 2.1 HDMI port, no displayport.
aorus GTX 1080ti 11gb (doesn't have hdmi 2.1)
48 Gbit/s hdmi cable
tv set to game mode
the monitor does not have an option to enable vrr or hdr, it just tells you if it is enabled or not by the input device signal.

but there is no option in nvidia control panel for sync/vrr?

I thought the 10 series cards could output vrr?

stooeh · 20 Nov 2021 at 01:24

You need a turing card or newer to get VRR over HDMI which rules the 1080 ti out sadly.

kenny saunders · 20 Nov 2021 at 02:31

stooeh said:
You need a turing card or newer to get VRR over HDMI which rules the 1080 ti out sadly.

ok that'll be why then, cheers.

DO you have any idea why the text looks worse on when I change it from 60hz to 120 hz, i know text looks worse on a tv but why even worse than that because of upping the hz?

stooeh · 20 Nov 2021 at 03:05

If its at 4K then 1080ti doesnt have 2.1 HDMI so not enough bandwidth for 4:4:4 120Hz so may just be dropping to 4:2:0 - should work at 1440p 120Hz fine I think. Not got my 1080ti anymore to check

kenny saunders · 20 Nov 2021 at 03:17

stooeh said:
If its at 4K then 1080ti doesnt have 2.1 HDMI so not enough bandwidth for 4:4:4 120Hz so may just be dropping to 4:2:0 - should work at 1440p 120Hz fine I think. Not got my 1080ti anymore to check

Again that sounds right, I just tried it at 1440p and although it was blurry because of the non-native res it didn't have the weirdness of before at 120hz. I'll wait until next gen for a new gpu. Thanks.

EsaT · 20 Nov 2021 at 09:01

kenny saunders said:
Again that sounds right, I just tried it at 1440p and although it was blurry because of the non-native res it didn't have the weirdness of before at 120hz.

Any chroma subsampling completely rapes coloured fine graphics (like text) on coloured background.

Full "4:4:4" colour sampling:
https://i.rtings.com/assets/pages/eh5HDv8m/text-chroma-4k-60hz-pc-mode-large.jpg
4:2:2
https://i.rtings.com/assets/pages/eh5HDv8m/text-chroma-4k-30hz-large.jpg
4:2:0
https://i.rtings.com/assets/pages/eh5HDv8m/text-chroma-4k-60hz-large.jpg

Braindead "panel upside down" BGR subpixel layout would be another one messing normal RGB subpixel tuned text rendering.
But that wouldn't be affected by refresh rate.

kenny saunders · 22 Nov 2021 at 12:57

stooeh said:
You need a turing card or newer to get VRR over HDMI which rules the 1080 ti out sadly.

It didn't occur to me that they existed but I just saw a DP to HDMI cable, would that work?

LuckyBenski · 26 Nov 2021 at 16:12

kenny saunders said:
It didn't occur to me that they existed but I just saw a DP to HDMI cable, would that work?

Sadly not. DisplayPort 1.4 only carries HDMI 2.0 in its signals. This means you'd be limited to the same features and bandwidth. 4k60 at 4:4:4, or 4k120 with 4:2:0 colour subsampling. Both 8 bit/SDR.