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.



3233 Comments For “G-SYNC 101”

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TC.exe
Member
TC.exe

Howdy! Thanks a bunch for a fantastic write-up. I’m trying to use the information here to create a generalised flow-chart for myself and just wanted to clarify something. If the FPS exceeds the refresh rate, and there is not an in-game or config fps limiter, is Reflex (if available) the next optimal solution? Thanks

olly44444
Member
olly44444

Hi there,

I play competitive shooters and have been following the posts on g-sync settings. I’m curious if these results apply to freesync also? I have a 240hz freesync Alienware monitor. Currently the configuration I am using is ; Freesync on, rtss 237fps cap, v-sync on in radeon software. Is the v-sync going to pace the frames the same way as it would with g-sync? or is it going to add additional latency.

arshevizard
Member
arshevizard

I’m new to PC gaming and not a tech savvy person. Currently using 240hz monitor (MAG 271QPX QD-OLED E2) to play single player games in 1440P.

My FPS in games usually 90 – 120 depending on the game. Should I enable adaptive sync and Vsync and Gsync NVCP as well? Also, my monitor have option to turn on/off DSC. Should I use DSC?

jeffoo3
Member
jeffoo3

what if the game im playing is capped at like 60fps or 120fps?, do i cap my fps at 57 or 117 or do i just set my monitor hz to 60/120?

ez4angelo
Member
ez4angelo

Hey, a CS2 player here…
Recently steam give this give for optimizing the game and also starts as an notification on the game when you have GSYNC enabled on your monitor and NVCPL:
https://help.steampowered.com/en/faqs/view/418E-7A04-B0DA-9032

I would like to kindly ask, what would be the best settings? It seems that an in-game VSYNC and Reflex do the work pretty well, but, how about FPS Limiters and Low Latency Mode?

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