GSync compatibility - another monitor lottery?

[Vexr]

I've been looking at the Samsung C34F791 (34" Ultrawide 100Hz FreeSync), and the biggest deal for me right now is GSync compatibility.

The messages are mixed regarding this particular panel and it's making me wonder if there's a bit of a lottery going on.

One site reviewing it says it works partially with GSync, in that it will lose display loading up a full screen game with FreeSync enabled, but FreeSync could be enabled once within a game and work fine (or on borderless windowed I assume).

On that GSync compatibility spreadsheet doing the rounds, one user say it works 100% no issue. Another says it works on FreeSync standard mode only (80Hz - 100Hz, aka pretty much useless), and even references someone else saying it works on ultimate mode only (48Hz - 100Hz), but not standard mode - possibly they got that the wrong way round.

Also of note is the site that reviewed the C34F791 and highlighted a GSync compatibility issue also identified the Samsung C34J791 as working without issue with GSync, even though it's the same monitor but with Thunderbolt.

So is GSync compatibility a lottery, like whether or not you get a monitor with intolerable back light bleed / dead pixels etc, or isn't it?

 

[varkanoid]

I think it is until manufacturers catch up and splash "gsync compatibility" all over the boxes. It feels a bit like nvidia caught them out unawares because as you know full well any little marketing advantage and it gets splashed all over the box. Bit like TV manufactures splashing "HD Ready" on the boxes making consumers think they are getting a Full capable HD TV when in fact it can only do 720p. It'll come wont be long till "Gsync Compatible" appears by manufacturers. I can hear the stickers being made now ready to slap on the boxes. Shouldnt take them long to go through their catalogue and test them themselves.

 

[Baddass]

You can only get a Gsync compatible certification if the VRR performance passes a range of tests and criteria set out by NVIDIA. it’s unclear if NVIDIA have to verify and certify a screen themselves but the initial list of 12 and the original press release about this implies they had a role in testing and verifying those initial models.

Display manufacturers will need to up their game when it comes to using adaptive sync whereas before it was largely a free for all with no real performance criteria. That’s why there’s a real mix of FreeSync performances out there as it’s been a very loosely controlled programme to date.

 

[Dwaindibbly]

I have this monitor and can confirm the losing display when loading a fullscreen game, it's easily fixed with a quick alt tab.

I use ultimate engine whilst capping my frame rate at 95 with afterburner. I've only really played BF5 and it all seems to be working OK, on the load screens I notice a flickering of the image but I can't recall seeing it in game

 

[Vexr]

I have this monitor and can confirm the losing display when loading a fullscreen game, it's easily fixed with a quick alt tab.

I use ultimate engine whilst capping my frame rate at 95 with afterburner. I've only really played BF5 and it all seems to be working OK, on the load screens I notice a flickering of the image but I can't recall seeing it in game

Very interesting you describe the exact same thing as the review site, but it's not mentioned on the GSync compatibility spreadsheet. I'm sure I could live with that issue if that's all it is.

I note AMD themselves don't show the C34F791 under their FreeSync supported monitors, but do with the C34J79X (which did get a clean bill of health for GSync):

https://www.amd.com/en/products/freesync-monitors

Makes me wonder if FreeSync on the former is just a tad glitchy even with AMD cards, and so problems have rolled over to / been exacerbated on NVidia cards.

How are frame rates under 48 fps on the C34F791 if you don't mind me asking? Is there some sort of low frame rate compensation / doubling of Hz back in to its FreeSync range?

 

[Dwaindibbly]

I couldn't say if I'm honest.

I had lowered the settings to get a constant 95fps before trying freesync and haven't changed them since enabling it.

I can try it with the settings cranked up for you next time I have a game, hopefully over the weekend

I'm using a 1080ti btw

 

[Vexr]

I couldn't say if I'm honest.

I had lowered the settings to get a constant 95fps before trying freesync and haven't changed them since enabling it.

I can try it with the settings cranked up for you next time I have a game, hopefully over the weekend

I'm using a 1080ti btw

That would be awesome if you could. I've seen this review where they say it has LFC but "flickers like crazy between 45-53 fps", though that was with an R9 290 and it sounds like FreeSync has problems on this monitor with AMD cards before Vega. Doesn't bode too well for GSync compatibility though, which I'd expect to be weaker than with any AMD card.

 

[efish]

So is GSync compatibility a lottery, like whether or not you get a monitor with intolerable back light bleed / dead pixels etc, or isn't it?

Seems like it at the moment as information, particularly with monitors that pre-date the update, can be problematic to find. With new monitors reviews and user feedback give more of a clear indication.

No amount of info. reduces the chance of being unlucky and getting a monitor with excessive glow, bleed and dead pixels so its not the same thing.

Its a lack of information rather than the curse of the computer gods that's the issue.

 

[Vexr]

Seems like it at the moment as information, particularly with monitors that pre-date the update, can be problematic to find. With new monitors reviews and user feedback give more of a clear indication.

No amount of info. reduces the chance of being unlucky and getting a monitor with excessive glow, bleed and dead pixels so its not the same thing.

Its a lack of information rather than the curse of the computer gods that's the issue.

Hopefully. If GSync-compatibility is indeed consistent across all monitors of a certain model, I'd say so. Though going by the compatibility spreadsheet vs what this review found, it looks like mileage may vary. Either that or it calls into question the validity of the spreadsheet, in which case misinformation is a problem.

 

[Vexr]

After seeing some more user testimony that the Samsung C34F791 has serious issues with GSync and managing to find a very decent deal on the C34J791, I've pulled the trigger on the latter. I was certainly swayed by this too:

https://www.eurogamer.net/articles/...esync-monitors-for-nvidia-graphics-cards-7044

Best ultra-wide FreeSync monitor: Samsung LC34J791

This Samsung VA-panel monitor boasts excellent contrast, flawless 48-100Hz FreeSync support on Nvidia graphics cards and very low input lag of 6ms. That's a big improvement over the 23ms of input lag reported on its predecessor, the CF791, which also exhibited flickering with Nvidia graphics cards. The 3440 x 1440 resolution is impressive too, with enough detail to justify the 34-inch span but not enough to require an incredibly high-end PC. Finally, the C34J791 also includes Thunderbolt 3 USB-C, so you can connect a laptop to the monitor while charging it with a single cable. All in all, a convincing modern ultra-wide, and one of the few we've seen to play nicely with Nvidia graphics cards.

I currently have no use for Thunderbolt whatsoever, but flawless Freesync on an NVidia card I certainly do Just hope the switch from IPS to VA isn't going to give me cause for regret.

Cheers for the offer to test the C34F791 @Dwaindibbly, but shouldn't be necessary now (at least not in my case).

 

[DmitryD]

Make sure you got Windows 10 as otherwise NVIDIA drivers won't support it!

 

[Dwaindibbly]

Cheers for the offer to test the C34F791 @Dwaindibbly, but shouldn't be necessary now (at least not in my case).

No worries, I didn't get time to test this weekend so I'm glad you found a decent deal for what seems to be the better of the two

 

[Vexr]

Make sure you got Windows 10 as otherwise NVIDIA drivers won't support it!

Windows 10 has long since been installed. I've already felt the benefits of DX12 - surprised any gamer wouldn't be on Win10

No worries, I didn't get time to test this weekend so I'm glad you found a decent deal for what seems to be the better of the two

I dug too deep online and since seen one person say the C34J791 has flickering issues on GSync. I'll found out soon enough for myself as it's en-route now.

 

[Vexr]

Annnd the C34J791 flickers like crazy on my 1070 Ti with ultimate mode Freesync. 'Flawless GSync compatibility' my arse.

There's a thread on reddit that seems to confirm my suspicion about panel lotteries for GSync:

https://www.reddit.com/r/ultrawidemasterrace/comments/an054d/samsung_cj791_or_cf791/

The flickering seems to be some kind of build lottery, I have it on GSYNC compatible and ultimate engine and I dont have any flicker.

Looks like I get another roll of the dice though as the monitor has an unrelated physical defect, so it's getting exchanged. Not feeling too hopeful though as no doubt their stock is all from the same batch.

 

[LadFromWales]

I hate to be the one to say this, but it definitely appears as though the flickering artifact you get when enabling G-Sync may be related to the GPU and how it gets on with the monitor.

My Zotac 1080 Ti didn't get on with an AOC AGON AG322QC4, flickered often enough to be a huge distraction.
I plugged the same monitor into another system which has a 1060, and played GTA Online for an hour, if it flickered I didn't notice! For transparency, I moved the 1060 system to the same location as the 1080 Ti system, and used all of its cables, so the only variable was the system.

 

[Vexr]

I'll hope not @LadFromWales - though sounds like another thing to consider. I'm thinking the monitor might be faulty as now turning on FreeSync (standard and ultimate) causes the display to dim, even with GSync disabled on the PC. Enabling GSync, the Hz reported in the screen's OSD is usually miles off in game FPS and fluctuating enormously.

 

[supra21]

I am looking into purchasing the Samsung CJ791. After doing some googling I have found sources that say that the CJ791 is Gsync compatible. Has there been any updates regarding compatibility with Nvidia gpu's? I have a 1080ti FTW3 Hybrid and I just want some definitive confirmation if gsync will work or not?

 

[Deus_rsf]

I bought it (the thunderbolt variant) and it's great (GTX 1080Ti MSI Gaming X, drivers 430.64) with the Ultimate Engine, and the inputlag is very low !
HOWEVER. The flickering issue at low framerates is definitely a problem. As far as I'm concerned, I was able to notice it even from 60 FPS to lower ! (though at 60 FPS it was extremely minor, not a problem)
The freesync delta was very generous though, I was able to maintain freesync with a 99FPS lock on Nvidia Framerate Limiter V2 + max prerendered frames = 1 (Don't use RivaTuner ! I love RTSS but it's bugged with freesync sadly..)
I still need to do some intensive tests, but I'd say it's a great Freesync monitor for games that you usually play at high framerates, because at 60FPS+ it's a treat ! And it really works very well.
(tested on DOOM 2016, Metro 2033, Bioshock, and plenty of other old and modern games) Low inputlag and very consistent experience.
Sadly a lot of games I play are locked at 60 FPS, or unlocked but just very difficult to run.. So I may return it :s
I really don't know if the flickering issue is a hardware problem or a lack of proper driver support, it's really tricky to say, especially since it also does it with AMD cards.
All this Freesync on Nvidia thing is super interesting though, Nvidia got a lot of **** on their G-Sync technology, but at least their technology worked well and consistently (more consistently).

Seeing it as a 60-100Hz Freesync monitor without LFC is a more honest way to sell it, unless a driver update or a firmware update shakes things up, if it can.

It's sad because there really isn't many options for good ultra-wide VRR that aren't insanely expensive, and the 144Hz model Samsung was supposed to be working on for years just.. doesn't exist.

Plus honestly, The VA panel feels like a downgrade on many aspects to me (I strongly prefer IPS)

EDIT : I tested again, and... It's weird, this time the screen almost didn't flicker on me anymore between 50 and 60 FPS, but still do flicker between 30 and 50 FPS but less than before (still noticeable though)
It seem to be relatively inconsistent, and linked to the use of LFC.
I'll have to do more precise testings on more games for a longer time.

 

[Vexr]

@Deus_rsf that sounds consistent with my experience, though as I later discovered it was borderless windowed mode that caused a lot of my FreeSync woes, which tended to disappear on exclusive full screen mode. In some exclusive full screen games LFC would be good enough that, other than a solitary flicker when going past 48 fps, it'd be fine.

Unfortunately there are a lot of games that are borderless full screen only. In the end I chose to downgrade my GPU and wait it out until NAVI arrives. Maybe the issue was only with my 1070 Ti being an unlucky card or something. There's a sizeable minority of folks who've had similar problems with borderless fullscreen GSync even on full GSync monitors in recent times.

That said, it'll be interesting to see if what happened with my card is happening with other Nvidia cards on this monitor.

 

[Deus_rsf]

So I tested more games, even did the CRU hack (could go from 48-100 to 30-100 actually !) but the problem is from the monitor.
I tested with my friend's PC which has a Radeon RX 580 Crimson ReLive latest version, exactly the same flickering problems at exactly the same ranges.
This time I did proper testing with the nvidia pendulum demo, and the results are clear for both cards, between 60 and 100 FPS the experience is amazing, below, it's flicker hell (more or less).
It's sad because I like this monitor, it looks great, but secured 60 FPS min for all my games is a huge requirement at this resolution, even with a 1080Ti !

Edit : haha, thanks to the pendulum demo I actually understood where the problem is coming from ! It's the way the screen handles backlighting !
Even in the ultimate engine range without triggering LFC, 50 Hz for example is much brighter than 100 Hz ! So when it goes to 40 FPS it goes to 80Hz, which is brighter than 50 Hz !
It's basically just the brightness of the monitor that is not properly set to follow the frequency precisely ! If it were, there wouldn't be any problems !