G-Sync windowed mode forced vsync (MPO)

Talk about NVIDIA G-SYNC, a variable refresh rate (VRR) technology. G-SYNC eliminates stutters, tearing, and reduces input lag. List of G-SYNC Monitors.
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nattax1
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Joined: 23 Jul 2022, 04:02

G-Sync windowed mode forced vsync (MPO)

Post by nattax1 » 23 Jul 2022, 08:36

Hello,

I’ve noticed that the framerate of games gets capped to the refresh rate of the monitor, if g-sync is
set to “Gsync Fullscreen + Windowed mode” and you play games in windowed or windows
borderless mode.

I’ve made sure that I haven’t enabled vsync globally, per game basis or in the game itself or any other
feature like fast-sync.

The games I tried (Portal 2, Bulletstorm, Counter-Strike Source) also don’t have NVIDIA reflex that
caps framerate when vsync is active.

The Framerate is instantly uncapped as soon as I go true fullscreen mode or set gsync to only
fullscreen mode.

So the framerate cap wouldn’t bothering me, but im curious if with “Gsync Fullscreen + Windowed mode” adds the typical dwm forced vsync again that you could normally disable since NVIDIA driver 461.09 (multiplane overlay).

Since i don’t have the equipment to measure the input delay, I would like to know if someone can
help me out with that or maybe knows if the framerate cap isn’t related to dwm forced vsync.

  • GPU: Asus RTX 2080 TI (No overclock)
  • OS: Windows 11@21H2 (Build 22000.739)
  • Displays: 2 (Both 144hz)
  • Current NVIDIA driver: 512.95 (DCH version)

nattax1
Posts: 4
Joined: 23 Jul 2022, 04:02

Re: G-Sync windowed mode forced vsync (MPO)

Post by nattax1 » 02 Sep 2022, 08:12

bump - anyone? :S

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RealNC
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Re: G-Sync windowed mode forced vsync (MPO)

Post by RealNC » 04 Sep 2022, 07:09

nattax1 wrote:
02 Sep 2022, 08:12
bump - anyone? :S
If you use NNvidia's "Ultra Low Latency" setting, it caps FPS to below refresh rate. Change it from "ultra" to "on" to get rid of the cap.
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nattax1
Posts: 4
Joined: 23 Jul 2022, 04:02

Re: G-Sync windowed mode forced vsync (MPO)

Post by nattax1 » 05 Sep 2022, 15:13

RealNC wrote:
04 Sep 2022, 07:09
nattax1 wrote:
02 Sep 2022, 08:12
bump - anyone? :S
If you use NNvidia's "Ultra Low Latency" setting, it caps FPS to below refresh rate. Change it from "ultra" to "on" to get rid of the cap.
I've just noticed i posted this in the G-Sync forum...in this case i use a freesync compatibel monitor, so it might be good to move the thread (But im sure the same problem will exist for G-Sync).

My Ultra Low Latency settings isn't enabled in the nvidia control panel (Not for any app and not globally).

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RealNC
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Re: G-Sync windowed mode forced vsync (MPO)

Post by RealNC » 06 Sep 2022, 04:51

nattax1 wrote:
05 Sep 2022, 15:13
I've just noticed i posted this in the G-Sync forum...in this case i use a freesync compatibel monitor, so it might be good to move the thread (But im sure the same problem will exist for G-Sync).
Since you're using the "g-sync compatible" support on an nvidia card, this is the correct forum section :)
My Ultra Low Latency settings isn't enabled in the nvidia control panel (Not for any app and not globally).
Then it appears MPO is not working? I don't know myself what the requirements are for it to work. I never use windowed mode.
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nattax1
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Re: G-Sync windowed mode forced vsync (MPO)

Post by nattax1 » 08 Sep 2022, 07:51

RealNC wrote:
06 Sep 2022, 04:51
My Ultra Low Latency settings isn't enabled in the nvidia control panel (Not for any app and not globally).
Then it appears MPO is not working? I don't know myself what the requirements are for it to work. I never use windowed mode.
Yeah thats what i want to find out. If multiplane overlay (MPO) isn't working when G-Sync windowsed mode is enabled.
The problem with many of the new 4k144hz displays is, that they're using DSC (Display Stream Compression) in order to achive this high bandwith with cables like displayport.

When you read further you will notice that at least on nvidia implementation that often makes alt+tab slow (When the Display Stream Compresion is used)... like 4-8 seconds. This is really annoying when you just wanna read some new message on the 2. display real quick.

So windowed mode would be much nicer option for that.

Personally i don't notice an increased input delay in windowed mode with g-sync windowed mode enabled even when reaching the fps limit of 144. But i could be wrong and just don't notice it and would love if someone could test that:

Test:
  • G-Sync windowed mode option enabled
  • Play the game in windowed mode or fullscreen windowed mode
  • No DirectX12 game because as far as i know they're handled differently but im not sure
  • No V-Sync (Ingame and Nvidia Control Panel)
  • No Low Latency
  • No FPS Limiter
  • Having 144FPS or the maximium fps of the max refreshrate of the display
And see if the input delay is like forced vsync or if its just normal.

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