G-Sync does not work at 4K/120 on the LG C9 OLED via HDMI 2.1 with my 3080

Rbk_3 · Sep 18, 2020

I was lucky enough to get a 3080, I also picked up a Mono Price HDMI 2.1 Cable. 4k/120 works fine for gaming with out G-Sync, but if it is turned on the screen goes black. I am on the most recent firmware.

This is highly disappointing. This was the whole reason I bought this TV and was anticipating this card so much.

Okii · Sep 18, 2020

I had no idea those TVs had GSync.

CrispyGamer · Sep 18, 2020

Damn that sux

hayabusi · Sep 18, 2020

Me neither, and I have one..

Brandino · Sep 18, 2020

Is there a very setting you need to turn on in the tv's menu?

Yerffej · Sep 18, 2020

Ramathevoice · Sep 18, 2020

Well, these cards are the very first with HDMI 2.1, so there are bound to be some kinks to work out.

Maybe there's a compatibility issue between the G-Sync protocol and the HDMI 2.1 VRR?

darkness · Sep 18, 2020

I'm pretty sure Freesync only works on nVidia via Display Port. The monitor has to officially support gsnyc to use hdmi.

Musician · Sep 18, 2020

Maybe LG will need to do a firmware update now that actual cards are out.

Or they'll shrug their shoulders and say "get a CX"...

curtismyhero · Sep 18, 2020

Does the screen only go black when you enable gsync from within the nvidia control panel? have you tried enabling/disabling HDR? I've got the c9 (and highly eager for the 3090), so curious if it's a bug, or a true tv/system limitation.

Lazybob · Sep 18, 2020

darkness said:
I'm pretty sure Freesync only works on nVidia via Display Port. The monitor has to officially support gsnyc to use hdmi.

The C9 is G sync compatible over HDMI. One of the only TVs Nvidia certified as so.

Rbk_3 · Sep 18, 2020

darkness said:
I'm pretty sure Freesync only works on nVidia via Display Port. The monitor has to officially support gsnyc to use hdmi.

You would be wrong my friend.

kenshee · Sep 18, 2020

Thanks for the heads up, that's a part of why I was looking forward to upgrading from my 1070 actually, since that one just missed the boat on supporting the feature. Here's hoping this gets sorted through updates, it would be very sad if it was only officially supported on the C9 by the GTX 20-series...

Ramathevoice · Sep 18, 2020

Musician said:
Maybe LG will need to do a firmware update now that actual cards are out.

Or they'll shrug their shoulders and say "get a CX"...

I'd be livid if they only did G-Sync for a single fucking generation of nVidia cards ^^

Wouldn't HDMI 2.1 VRR kind of obviate the need for G-Sync though?

Rbk_3 · Sep 18, 2020

curtismyhero said:
Does the screen only go black when you enable gsync from within the nvidia control panel? have you tried enabling/disabling HDR? I've got the c9 (and highly eager for the 3090), so curious if it's a bug, or a true tv/system limitation.

No, it just goes black when I launch a game. Desktop is fine, then I can press the Windows key and the desktop comes back.
I am going to play around with making a custom resolution in CRU. I did have it OC'd to 66hz and it worked fine so it should hopefully work at like 100hz or something.

Neon Octopus · Sep 18, 2020

Thats no good. Hopefully it gets ironed out. Does anyone know if it works with a CX?

pswii60 · Sep 18, 2020

Welp that's really really bad to have that confirmed :(

Same reason I ordered one too. 4k/120/Gsync holy grail. Hope LG fixes this.

Lazybob · Sep 18, 2020

If the C9 which is "Gsync Compatible" has issues it doesn't bode well for other HDMI 2.1 TVs to have VRR function out the box just because the 3000 series use HDMI 2.1. I know some people assumed that to be the case.

Mr.Deadshot · Sep 18, 2020

darkness said:
I'm pretty sure Freesync only works on nVidia via Display Port. The monitor has to officially support gsnyc to use hdmi.

There are Freesync monitors that are compatible to GSync - but it can be pretty sketchy. Better get a "true" G-Sync.

MadZero · Sep 18, 2020

Musician said:
Maybe LG will need to do a firmware update now that actual cards are out.

Or they'll shrug their shoulders and say "get a CX"...

I believe the CX's HDMI bandwidth spec is even lower than the C9

40 Gbps (CX) vs 48 Gbps (C9)

TBH I don't know how this affects Gsync.

Maybe EvilBoris or P40L0 can enlighten us.

Fantastical · Sep 18, 2020

I'm picking up a CX precisely for this purpose, so watching this thread. :)

curtismyhero · Sep 18, 2020

Rbk_3 said:
No, it just goes black when I launch a game. Desktop is fine, then I can press the Windows key and the desktop comes back.
I am going to play around with making a custom resolution in CRU. I did have it OC'd to 66hz and it worked fine so it should hopefully work at like 100hz or something.

Gotcha. I would try to isolate it down to see if it's actually gsync, or something else. This would be filtering through different resolutions (i.e. 1440p/120hz), as well as HDR, and gsync itself. I do know that HDMI 2.1 cables are kind of a gray "not so certain" area, where from what I've gathered, require more expensive cables once you go past a certain length. I'd also tinker around with the cable if it's longer than 6ft. I hope this helps!

Ramathevoice · Sep 18, 2020

Reminder for everyone still asking: The LG 9 & X series OLEDs are compatible with G-Sync over HDMI. They are the only displays capable of this.

P40L0 · Sep 18, 2020

Madridy said:
I believe the CX's HDMI bandwidth spec is even lower than the C9

40 Gbps (CX) vs 48 Gbps (C9)

TBH I don't know how this affects Gsync.

Maybe EvilBoris or P40L0 can enlighten us.

You won't have any bandwidth issue if you're going to pair it to an Xbox Series X or PS5.

Euler007 · Sep 18, 2020

Are you sure VRR isn't operating when you're at 4k/120?

Michael B · Sep 18, 2020

I'm hoping to use a RTX 3 series with my C9 like you. Hopefully this is something that can be fixed relatively quickly by either Nvidia or LG or both.

Also as a reminder, Nvidia lists both the 9 series and X series OLEDs as VRR capable within a 40hz-120hz range at 4k unless I'm reading the chart wrong:

NVIDIA GeForce G-SYNC Gaming Monitors

Search for GeForce G-SYNC gaming monitors.

www.nvidia.com

Ramathevoice · Sep 18, 2020

Michael B said:
I'm hoping to use a RTX 3 series with my C9 like you. Hopefully this is something that can be fixed relatively quickly by either Nvidia or LG or both.

Same. Keeping an eye on this.

MadZero · Sep 18, 2020

P40L0 said:
You won't have any bandwidth issue if you're going to pair it to an Xbox Series X or PS5.

Yea I agree.

However, The case here is G-sync with a 2.1 HDMI capable PC @ 4k120Hz

Wowzors · Sep 18, 2020

I bet it requires an EDID hack until LG/Nvidia get to the point of caring.

pswii60 · Sep 18, 2020

Rbk_3 said:
No, it just goes black when I launch a game. Desktop is fine, then I can press the Windows key and the desktop comes back.
I am going to play around with making a custom resolution in CRU. I did have it OC'd to 66hz and it worked fine so it should hopefully work at like 100hz or something.

Do you have Gsync set to enable only in full screen mode, or both full screen and windowed? If the latter, and it only goes blank when you launch a game, it indicates a driver issue. If the former, it could be either.

dseed · Sep 18, 2020

I was under the impression that C9 at 4K can only do 40-60 gsync and at 1440p 40-120

Ramathevoice · Sep 18, 2020

Hey Rbk_3: I just checked the nVidia website for the C9 G-Sync compatibility and it says:

8. Select Display > Change resolution and apply one of these modes:

2560x1440 @ 120Hz for a 40-120Hz Variable Refresh Rate range

3840x2160 @ 60Hz for a 40-60Hz Variable Refresh Rate range

So it's possible either the current G-Sync implementation or the TV's current firmware only allow for those two modes, for now.

Jehuti · Sep 18, 2020

dseed said:
I was under the impression that C9 at 4K can only do 40-60 gsync and at 1440p 40-120

This was misinformation from DF. Its been proven otherwise since then.

P40L0 · Sep 18, 2020

Madridy said:
The case here is G-sync with a 2.1 HDMI capable PC @ 4k120Hz

I think it depends from the PC configuration.
The NVIDIA 3080 is so brand new I don't actually know how it's working right now, bandwidth wise.

What I know is that both XSX and PS5 HDMI 2.1 bandwidth will be in the realm of 40Gbps max, and not 48Gbps.
This should never saturate (and create black screens or issues) both for C9 and CX models.

Xtortion · Sep 18, 2020

dseed said:
I was under the impression that C9 at 4K can only do 40-60 gsync and at 1440p 40-120

That's over HDMI 2.0. LG has stated that the 2019 OLEDs can do 4K 40-120 VRR over HDMI 2.1.

Exentryk · Sep 18, 2020

Don't need Gsync when you have VRR.

Stormbrewer · Sep 18, 2020

I mean, from this thread we knew only 60hz VRR was supported for C9 on HDMI 2.0, and 120 support on HDMI 2.1 was only theorized through a software update that may or may not come:

digitalrelic said:
I think this may be useful after the kind of confusing/controversial DF 120fps video.

For Variable Refresh Rate, CX Supports Freesync Premium, HDMI 2.1 VRR, and G-SYNC. C9 only supports HDMI 2.1 VRR and G-SYNC.

CX Supports 4K/120hz VRR with HDMI 2.0. C9 Supports 4K/60hz VRR with HDMI 2.0.

They expect both CX and C9 to support 4K/120hz VRR with HDMI 2.1 on next-gen consoles.

LG CX OLED vs LG C9 (rtings.com)

I think this may be useful after the kind of confusing/controversial DF 120fps video. Identical aesthetics. Identical input ports. CX limits HDMI 2.1 bandwidth to 40Gb/s. C9 has full 48Gb/s on all four HDMI 2.1 ports. Not expected to make a noticeable difference. Marginally lower peak...

www.resetera.com

Hoping it gets patched in since I've got a C9, but not sure it will or not.

Ramathevoice · Sep 18, 2020

Exentryk said:
Don't need Gsync when you have VRR.

Yeah but does the VRR work? How is it enabled on the source-side? Through the driver? Is it automatic?

Lazybob · Sep 18, 2020

dseed said:
I was under the impression that C9 at 4K can only do 40-60 gsync and at 1440p 40-120

40-60 at 4k only because there were no HDMI 2.1 sources. Up until now it was impossible to test 4k 120 properly as older hdmi outputting devices could only output 4k 60.

Exentryk · Sep 18, 2020

Ramathevoice said:
Yeah but does the VRR work? How is it enabled on the source-side? Through the driver? Is it automatic?

Should be automatic. That said, I haven't gotten my 3080 yet.

Jedi2016 · Sep 18, 2020

Exentryk said:
Don't need Gsync when you have VRR.

Gsync is VRR.

Ramathevoice · Sep 18, 2020

Jedi2016 said:
Gsync is VRR.

As far as I can tell G-Sync is a different implementation of VRR than what's part of the HDMI 2.1 spec.

pswii60 · Sep 18, 2020

Stormbrewer said:
I mean, from this thread we knew only 60hz VRR was supported for C9 on HDMI 2.0, and 120 support on HDMI 2.1 was only theorized through a software update that may or may not come:

LG CX OLED vs LG C9 (rtings.com)

I think this may be useful after the kind of confusing/controversial DF 120fps video. Identical aesthetics. Identical input ports. CX limits HDMI 2.1 bandwidth to 40Gb/s. C9 has full 48Gb/s on all four HDMI 2.1 ports. Not expected to make a noticeable difference. Marginally lower peak...

www.resetera.com

Hoping it gets patched in since I've got a C9, but not sure it will or not.

That's talking with HDMI 2.0

dseed · Sep 18, 2020

Lazybob said:
40-60 at 4k only because there were no HDMI 2.1 sources. Up until now it was impossible to test 4k 120 properly as older hdmi outputting devices could only output 4k 60.

Got it. Hopefully it's something that can be patched

pswii60 · Sep 18, 2020

OP can you try and see what happens at 100hz?

Jedi2016 said:
Gsync is VRR.

I think they mean HDMI VRR, which is a different implementation, and a standard part of the HDMI 2.1 specification.

TheOne · Sep 18, 2020

Ramathevoice said:
As far as I can tell G-Sync is a different implementation of VRR than what's part of the HDMI 2.1 spec.

Nvidia does VRR via G-sync only so I'm not sure what your goal is...

Michael B · Sep 18, 2020

Ramathevoice said:
Hey Rbk_3: I just checked the nVidia website for the C9 G-Sync compatibility and it says:

So it's possible either the current G-Sync implementation or the TV's current firmware only allow for those two modes, for now.

Is this the page you were looking at? https://www.nvidia.com/en-us/geforce/news/g-sync-compatible-2019-lg-tv-available-now/

I'm hoping that since this was written a year ago when only HDMI 2.0 cards were available, they were just writing the instructions with the HDMI 2.0 spec limit in mind. Who knows though, we can only cross our fingers at this point until we get an official response.

1-D_FE · Sep 18, 2020

P40L0 said:
You won't have any bandwidth issue if you're going to pair it to an Xbox Series X or PS5.

Or even a PC. I remember reading an article recently where Nvidia changed things to allow output at 10bit when connected to an HDTV. The only real concern was supposedly addressed.

Ramathevoice · Sep 18, 2020

TheOne said:
Nvidia does VRR via G-sync only so I'm not sure what your goal is...

Do they? I mean I know they always have, but since they now have HDMI 2.1 GPUs, doesn't that also make them compatible with the HDMI 2.1 VRR standard? I'd love to know if that's the case :)

Deleted member 13101 · Sep 18, 2020

Well, it is technically refreshing zero frames per second right now. Perhaps a little too variable, then. Hope it gets sorted out soon.

G-Sync does not work at 4K/120 on the LG C9 OLED via HDMI 2.1 with my 3080

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