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.



1948 Comments For “G-SYNC 101”

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Evok99
Member
Evok99

I just purchased the new Viewsonic XG2431 that features the blurbusters 2.0 approval. I plan on setting up the PureXP+ tomorrow to play with Overwatch. I can max Overwatch out at about 340fps consistently. Do you have any recommendations in how to setup gsync and PureXP+ for the lowest framerate? Should i cap my frames to 237fps with gsync and vsync enable even though I can get a much higher frame rate?

Maybe I would be better off with a 360hz monitor and no light striving? Thank you. This is all new to me.

roro13200
Member
roro13200

hello I wanted to know in nvcp, the refresh rate we must put it on which option? app-controlled or higher? I have an asus and there is a trace free option that adds input lag?
thank you for your work!

blz
Member
blz

Hello,
I play at 250-290 fps on valorant/csgo, 190 fps on valorant on a MSI G24C monitor should I use freesync (gsync compatible) when my frame rate is way above my 144hz refreshrate? Will the added input lag be worth the lesser tearing?

reaxtic
Member
reaxtic

Hi,
best settings for low input lag is a Gsync + LLM + V-sync in NVCP?

rocky.gaoa
Member
rocky.gaoa

hi,you said
“In-game Settings:
Disable all available “Vertical Sync,” “V-SYNC,” “Double Buffer,” and “Triple Buffer” options.”

does it mean prohibit the V-Sync working finally?

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