G-SYNC 101: G-SYNC Fullscreen vs. Borderless/Windowed


DWM Woes?

Requested by swarna in the Blur Busters Forums, is a scenario that investigates the effects of the DWM (Desktop Windows Manager, “Aero” in Windows 7) on G-SYNC in borderless and windowed mode.

Unlike exclusive fullscreen, which bypasses the DWM composition entirely, borderless and windowed mode rely on the DWM, which, due to its framebuffer, adds 1 frame of delay. The DWM can’t be disabled in Windows 10, and uses it’s own form of triple buffer V-SYNC (very similar to Fast Sync) that overrides all standard syncing solutions when borderless or windowed mode are in use.

To make sure this was the case, all combinations of NVCP and in-game V-SYNC, as well as the Windows 10 “Game Mode” and “fullscreen optimization” settings were tested to see if DWM could be disabled, and tearing could be introduced; it could not be, so Game Mode and fullscreen optimizations were disabled once again, and NVCP V-SYNC was re-enabled across scenarios for consistency’s sake.

The question is, does DWM add 1 frame of delay with G-SYNC using borderless and windowed mode?

Blur Buster's G-SYNC 101: Input Latency & Optimal Settings
Blur Buster's G-SYNC 101: Input Latency & Optimal Settings

Overwatch, shows that, no, with G-SYNC enabled, both borderless and windowed mode do not add 1 frame of delay over exclusive fullscreen. Standalone “V-SYNC,” however, does show the expected 1 frame of delay.

CS:GO was also tested for corroboration, and ought to have the same results, as DWM behavior is at the OS-level and should remain unchanged, regardless of the game…

Blur Buster's G-SYNC 101: Input Latency & Optimal Settings
Blur Buster's G-SYNC 101: Input Latency & Optimal Settings

Sure enough, again, G-SYNC sees no added delay, and V-SYNC sees the expected 1 frame of delay.

Further testing may be required, but it appears on the latest public build of Windows 10 with out-of-the-box settings (with or without “Game Mode”), G-SYNC somehow bypasses the 1 frame of delay added by the DWM. That said, I still don’t suggest borderless or windowed mode over exclusive fullscreen due to the 3-5% decrease in performance, but if these findings are true across configurations, it great news for games that only offer a borderless windowed option, or for multitaskers with secondary monitors.



3072 Comments For “G-SYNC 101”

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HopelessNinersFan
Member
HopelessNinersFan

Hi!

Thank you for the guide, it’s definitely made life much easier for me. I do have some confusion though. I have a 4080 SUPER, 32 GB RAM, i9 13980HX, and 240 HZ display – I’m quite proud of it. It mentions to enable Reflex if available or Low-Latency mode if FPS doesn’t always exceed the refresh rate, but how does that fit with setting a FPS limiter to limit the FPS regardless? I apologize in-advance if I’m misinterpreting, I’m still relatively new to PC gaming on a more advanced level. Furthermore, is Reflex even worth it if my 4080 isn’t ever anywhere near getting pinned? I heard Reflex only has an impact if your GPU is at 99%. Thanks again!

Regards,

Herconomicon
Member
Herconomicon

Do you recommend v-sync set to ON globally or per application ?

Vizima
Member
Vizima

So, I’ve been doing a lot of testing over the past few weeks. My PC specs are: Intel Core i7-13700k and my monitor is an Asus 240Hz OLED. First off, I want to thank you for the guide, it started my hyperfocus of testing a lot stuff xD. I stumbled upon something peculiar while playing Apex Legends.

When I cap my framerate (I use RTSS for this) and enable both G-Sync and V-Sync in the NVIDIA Control Panel, and then select Reflex in-game, my framerate gets capped at 225, as the guide suggests. It feels incredibly smooth, but I noticed something strange – I could NOT bunny hop anymore (on controller). Turning off V-Sync allows me to bunny hop again, but I dislike the drop in smoothness, so I decided to try some other options.

The first thing I tried was disabling Reflex altogether. Despite expecting Reflex to reduce input delay, its absence actually allowed me to bunny hop again (which I consider an indicator of low input delay). Then, I decided to re-enable everything – G-Sync, V-Sync in NCP, and Reflex in-game – and capped my framerate in RTSS to 200. To my surprise, I found that I could bunny hop once again, experiencing low input delay and maintaining very smooth gameplay. Can anyone explain what’s happening here? Because with the exact same settings at 225, I couldn’t achieve the same result.

Here are my MSI Afterburner benchmark results while playing in-game:

200 FPS (capped in RTSS)
Average FPS: 198
1% Low FPS: 185
0.1% Low FPS: 166

Thanks a lot!

toby23
Member
toby23

If I have a 120 Hz monitor with G-Sync and can achieve 115fps average in a game, is there any negative to locking the framerate to 59fps with RTSS to lower power consumption and smooth out Frametime?
Running unlocked in MSFS results in the Frametime jumping around all over the place but locking to 59 fps makes it steady.

PS Super article, thank you so much for keeping it updated.

Ryan Le
Member
Ryan Le

In Sea of Thieves, I have V-Sync turned off, but there is also an option to set the buffering to either double or triple, and there’s no off option. I set it to double buffering, but do I still need to enable V-Sync in NVCP? Would the in-game double buffering option (with in-game V-Sync off) conflict with NVCP V-Sync since it’s also running on double buffering?

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