[Thread Superseded] G-Sync 101 w/Chart (WIP)

[jorimt]

True. Thanks for the input.

A mystery it seems, and something worth further investigation on my part. I'll be sure to update the minute I discover anything further.

[gecko]

Awesome work! thanks for the info! I've been testing Rainbow Six Siege in the ASUS PG248Q:

A) G-Sync on + V-Sync on (only in NVCP) + RTSS 178 FPS limit (overclock ON = 180Hz)

B) G-Sync on + V-Sync on (only in NVCP) + RTSS 142 FPS limit (overclock OFF = 144Hz)

C) G-Sync on + V-Sync off + non FPS limiter (overclock ON = 180Hz)

D) G-Sync on + V-Sync off + non FPS limiter (overclock OFF = 144Hz)

But i'm confused because I feel less input lag with option C (the correct option must be A or B )
I hope to see test results for this game someday, thanks again, great work!

PC- specs:
GTX 1070
RAM 16GB 2400 Mhz
i5 4670k @ 4.2Ghz (oced)

[jorimt]

@gecko,

I'm glad you found my OP useful.

A new development from another tester's video (http://forums.blurbusters.com/viewtopic ... =60#p24063) has posed the possibility that RTSS is adding 1 frame delay, even with G-Sync. It may or may not be the case, but that could be what you are experiencing. I'm currently in contact with the video's creator, and will update here when I know more.

As for less latency with option "C," are you even close to reaching 180 fps at your current in-game settings? If not, you don't need a framerate limiter anyway, and G-Sync + v-sync on at 180 Hz will suffice. The fps limit is only required if the game in question can sustain the max fps of your display the majority of the time. For instance, those averaging 80 fps at, say, 144 Hz, need not set an fps limit.

[vorob]

Maybe at least here i could get some answers:

Code: Select all

Acer Predator G9-593
Intel Core i7-6700HQ (2.6Ghz/3.5Ghz) (https://goo.gl/dehk14)
Nvidia GeForce GTX 1070 (8Gb GDDR5) (https://goo.gl/z2aEFL)
15.6inch 1920x1080 (G-Sync) (IPS)
16Gb DDR4-2400 / PC4-19200 (2x ACR24D4S7S8MB-8)
Windows 10 x64
Nvidia driver - 378.49

So, sometimes, extremely rare, while i'm playing i'm getting these blackouts. Screen will just go black and then will turn on again. Happens faster then a second. I was playing Resident Evil 7 today and it happened once. Earlier i was playing Ghost Recon Closed Beta and it happened when i was using my drone.

So its totally random and rare, but still i worry.

I think is has smth to do with fps drops. Cause on resident evil 7 it happened when i enabled stream and my fps dropped from stable 40 to 32 and all around. After this i started having blinks from time to time. So i conducted a test:

I've installed quake ii and binded 2 keys: one will lock fps on 5 and another one on 90. And started changing them fast, and this summoned blinks:

https://www.youtube.com/watch?v=kOJGOxuCfWk

And additional issue, dunno if it somehow connected:

I’m using msi afterburner to overclock my gpu and assigned 2 keys for switching overlock profiles, default and overclocked.

And when g-sync is enabled I’m getting quick blackout when I switch profile. Nothing like this when g-sync if off. Take a look: https://youtu.be/kg_0kXi4U88

Made some further testing. Launched quake II and tried same thing with g-sync ON, nothing happened. Then i've lowered fps to 5 and switched OC profile once again, and this time i got same blackout thing.

[jorimt]

Sounds like a laptop specific issue; could be a hardware issue on that model, a driver bug, or both. I did look up the G9-593, and there have been previous complaints of screen flickering and blackouts:
https://community.acer.com/t5/Predator- ... m-p/482027

[Soss]

Hello Jorim,

Thx a lot for the info and the testwork you put into this thread !
I had the tearing issue as well, in CS:GO and BF-1 it was very noticeable, in my setup it started at 85 - 90 fps.
What I don't understand is that other people are not having these problems or are not reporting them ... If it is a G-SYNC driver issue, everybody with a G-SYNC monitor should start complaining ... On top of that, I asked 2 friends with a G-SYNC monitor to test this and they experience no problems. Now I start wondering that I have bad hardware (videocard, monitor, G-SYNC module in monitor, ...) and that your fix does just hide the problem ...

I recently bougth this new PC and monitor and can still RMA ...

My setup :
- Core i5-7500
- 16 GB RAM
- MSI B250M PRO-VH
- Gigabyte Geforce GTX 1060 6 GB
- ASUS PG2480Q
- latest NVidia drivers

What I did notice thought, is that I seem to get tearing only when I'm capping my framerate at a value below my refresh rate to get a stable fps and G-SYNC working (V-Sync off). If I tweak my game settings so that I get an fps around the same value below my refresh rate (G-sync ON, V-sync OFF) I do not notice any tearing although fps is the 'same' so G-SYNC should behave the same ... does framecapping has something to do with this ? (I used in game framerate capping in Overwatch and BF-1)

Another thing to note is the behaviour of my setup when my fps is well above my refresh rate (say 170fps/144Hz) with V-sync OFF I get a lot of tearing (in contrast to what other people are saying that once above 144Hz tearing is hardly noticeable ...). Could this be related to the other issue and indicate faulty hardware?

Do you experience the same behaviours ?

[jorimt]

@Soss,

You're system is probably fine. G-Sync issues vary because of differences in individual system configurations, and their ability or inability to output consistent frametimes, G-Sync or no G-Sync. It can also depend on the given game; G-Sync can only sync what the system is outputting to the display.

As for G-Sync + vsync on being a "fix [that] just hides the problem," G-Sync + v-sync on IS G-Sync, and G-Sync + v-sync off is actually a hastily implemented "feature" released due to popular demand, which, for a variety of reasons (most which were described in my OP), will not remain 100% tear-free, regardless of configuration. Again, due to system differences, G-Sync + v-sync off may tear at different framerates or tear less per game/system, but it's still going to tear. Tearing is simply more than one frame being displayed at the same time on the display.

Regarding your observance of extreme tearing, even well above your native refresh rate (with G-Sync off), no, this would not be indicative of a display or hardware issue. Tearing starts to diminish at 144 Hz when you're getting framerates at around 300+. That, and again, frametime delivery is king here, which is going to vary heavily from game to game, and system to system.

I'd advise you launch a game like CS:GO with v-sync off, put it at the lowest settings, set "fps_max 600," and see if you experience less tearing then.

I'd also advise you to research more about frametimes, and their impact on performance. There's a great article here that lays it all out:
http://techreport.com/review/21516/insi ... nchmarking

[Soss]

Jorim,

I can totally agree with what you are saying. It just seems that on my individual system the issue is more prevelant when capping my fps (the gpu is outputting a semi-'fixed' framerate) than when my fps fluctuates around the same framerate.

Another problem that I face with my setup is these "mini shade-like waves (1 horizonal pixel high)" running from top to bottom over the screen. I don't know what to call them ... are these scan lines ? moire ? The effect comes and goes, sometimes when I change the refresh rate , sometimes by itself. I have it only when G-SYNC is active when running my monitor on 144 Hz or 180 Hz.
I got rid off them by lowering the monitor's refresh rate to 143,900Hz in the Nvidia control panel. ('Change resolution' - 'Select 1920-1080 and 144Hz' - 'Customise' - 'Enable resolutions ...' - 'Create custom Resolution' - 'Timing - Manual' - '143,900Hz')
Any idea what these are? What is causing them? And if my solution will not cause any other trouble? I noticed that changing the refresh rate this way also changes the 'pixel clock', does that have anything to do with it?

Thx again, really appreciate it !

[knypol]

I feel a bit lost in a GSYNC technology. Do I understand correctly that with gsync on and vsync off with 2-3 fps cap below refresh rate i will have tearing? To avoid teraing i should use gsync on + vsync on with fps cap 2-3 below? Will i have any input lag with gsync on + vsync on?

[jorimt]

Jorim,

I can totally agree with what you are saying. It just seems that on my individual system the issue is more prevelant when capping my fps (the gpu is outputting a semi-'fixed' framerate) than when my fps fluctuates around the same framerate.

Another problem that I face with my setup is these "mini shade-like waves (1 horizonal pixel high)" running from top to bottom over the screen. I don't know what to call them ... are these scan lines ? moire ? The effect comes and goes, sometimes when I change the refresh rate , sometimes by itself. I have it only when G-SYNC is active when running my monitor on 144 Hz or 180 Hz.
I got rid off them by lowering the monitor's refresh rate to 143,900Hz in the Nvidia control panel. ('Change resolution' - 'Select 1920-1080 and 144Hz' - 'Customise' - 'Enable resolutions ...' - 'Create custom Resolution' - 'Timing - Manual' - '143,900Hz')
Any idea what these are? What is causing them? And if my solution will not cause any other trouble? I noticed that changing the refresh rate this way also changes the 'pixel clock', does that have anything to do with it?

Thx again, really appreciate it !

Not sure, possibly pixel inversion artifacts common to TN panel technology. Google it, and see if it looks like what you're experiencing. If any other regular on the forum spots your post, perhaps they might know more and chime in.

I feel a bit lost in a GSYNC technology. Do I understand correctly that with gsync on and vsync off with 2-3 fps cap below refresh rate i will have tearing? To avoid teraing i should use gsync on + vsync on with fps cap 2-3 below? Will i have any input lag with gsync on + vsync on?

Yes, you'll experience tearing (partial and full) with G-Sync + v-sync off, no matter the fps limit. No, you won't ever have tearing with G-Sync + v-sync on, and with an in-game limiter set 2-3 fps below your max refresh, you will have no additional input latency.

Also note that fps limits are only necessary for games where your system can sustain fps at or above your maximum refresh rate. If your system can only sustain an average framerate of 80 fps on a 144Hz monitor, for instance, you will have no additional input latency, whether you have an fps limit in place or not.