Blur Buster's G-SYNC 101 Series Discussion

[daninthemix]

Agreed.

The lack of detailed information directly from Nvidia on these points and others with G-SYNC is what drove me to do the research and write the article myself.

To be fair though, Nvidia has explained a lot of this, albeit in vague (difficult to find) PR form. But then again, if they had tried to break it down like I did, the average user probably wouldn't have the patience to fully absorb and comprehend the limitations of G-SYNC anyway.

Darned if they do, darned if they don't situation really.

This is why what Nvidia could at least do (and should do, in my opinion) is offer an official, supported frame-rate limiter in the NVCP, and enable it by default when G-sync is turned on.

They ought to meet us half way (at least) in getting this stuff sorted.

I realise the existing driver-level limiter has input lag, but so does v-sync and at least it would get rid of the stutter (heck - perhaps they could spend some time actually developing a decent driver-level limiter with low input lag).

[jorimt]

But then you run the risk of uninformed users misunderstanding further, and the more informed users complaining that they can't play uncapped with G-SYNC enabled due to the mandatory/automatic FPS limiter, and that it adds more lag than RTSS.

And while it is true Nvidia has an existing driver-level framerate limiter, it doesn't work well with G-SYNC currently, in fact, it tends to clash by using some form of it's own frame pacing, and it increases latency to near uncapped V-SYNC levels. So in enforcing a hard automatic FPS limit (sure, maybe only with the G-SYNC + V-SYNC combo), Nvidia would only really be remedying the stutter some users on some lower refresh rate G-SYNC monitors experience when their framerate exceeds the refresh rate, and only if they aren't using an in-game or external FPS limiter.

As for a low-latency driver-level limiter, it isn't close enough to the engine-level to reduce latency. They'd have to switch to a CPU-level limiter (which RTSS already is, and it still doesn't reduce latency as much as an in-game limiter), and they don't seem too keen on furthering their existing limiter, as they have yet to expose it officially (this has been the case for years now).

Bottom-line, there is no easy answer here, which is probably why they have yet to addressed it.

Is what it is until it's something else, really.

[daninthemix]

I have one more question - I have two monitors (the other a standard non-G-sync 60hz 1080p). As part of my troubleshooting, I moved it off the GTX1080 onto the iGPU.

Do you have any recommendations for multi-monitors? (the second monitor is only used for work, never gaming).

Thanks for all your help, knowledge and advice by the way!

[jorimt]

G-SYNC and dual monitor setups isn't great honestly, a lot of potential buggy behavior. Less of an Nvidia issue and more of an OS limitation currently.

You'll have better luck with matching refresh rate screens, however, which is what I assume you already have (4k 60Hz G-SYNC display, 60Hz non-G-SYNC display).

For now, I'd recommend plugging the G-SYNC monitor in as the primary display. If any other issues crop up, let us know.

[daninthemix]

Yes both 60hz, and G-sync is currently the primary. Shall I leave the secondary on the iGPU so that the NV driver doesn't have to worry about it?

[jorimt]

Up to you, but probably not a bad idea (maybe even pretty clever if it works as intended) if you'll only be using the secondary monitor for non-gaming purposes.

[daninthemix]

Gah, Burnout Paradise stutters like crazy with an FPS cap.

To top it off, disabling G-sync (setting 'fixed refresh') on a game profile appears to disable it entirely, system wide.

Man, when I bought this monitor I didn't realise configuring it would become a lifelong endeavour.

EDIT: ah, turn off G-sync in NV Inspector (just change 'Application State'). Doing it in NVCP on a game profile appears to change the 'Global Feature' to OFF.

[jorimt]

Yeah, I believe Burnout Paradise is limited to 60-62 FPS internally, so an external limit on top of that may or may not play nice in that very specific (thankfully rare) instance. Not that it currently helps you, but the great thing about 60Hz/FPS on a 100HZ+ G-SYNC monitor, is it avoids that issue; 4k/144Hz G-SYNC is coming soon enough though.

I've also noticed the Nvidia per-profile options such as the G-SYNC/Fixed Refresh and ULMB states are prone to buggy behavior. I've tried per profile ULMB in the past, for instance, and it either didn't work or applied to every game. Glad to hear you discovered that workaround however.

[Chief Blur Buster]

Yep...

In order of preference for GSYNC/FreeSync smoothness with fixed-framerates:

1. Let the game cap the frame rate (whether configurable or by forced limitation)

2. If that fails, use an external frame rate cap utility (RTSS preferred)

_ALWAYS_ try to have headroom when using VRR to smooth fixed-framerate games. 75Hz+ GSYNC works much better with 60fps locked games. The use of 60Hz GSYNC often works terribly with 60fps-limited games, since there's no headroom for VRR to play its stutter-smoothing magic.

Higher Hz headroom just simply eliminates a lot of hassle and headaches trying to smooth stutter for frame rates near a GSYNC/FreeSync monitor's maximum Hz. Eliminates a lot of fiddling for such particular fussy games. Maybe see if your 4K GSYNC monitor is overclockable to 65Hz GSYNC? That may make your "imprecise 60fps capped" games run much smoother. This will require experimentation with a CRU.

[daninthemix]

I settled on disabling G-sync globally, and only enabling it on games that I know are in risk of dropping below 60fps (Far Cry 3, etc), along with a 57fps cap where beneficial.

Unfortunately there's still not much choice around 4K G-sync and overclocking my monitor was one of the first things I tried - wouldnt even go to 61hz (pretty much flatout says it isn't OCable on the Acer specs too).