G-SYNC no longer capping frames at 144 when in Windowed?

[dmbr]

Currently, my monitor *always* says it's in GSYNC mode, even when a game is not running.

When I play Team Fortress 2 in Windowed mode, my PG278Q still reports that it is in G-SYNC mode, but my frames no longer cap themselves at 144.

Does this mean that GSYNC has changed or that GSYNC is not really functioning in windowed mode?

Frames are still capping at 144 when running in Fullscreen mode.

I'm running the latest nvidia drivers 359.06

[nimbulan]

That's just the way the drivers function. There's a separate option to enable G-sync in widowed mode in the drivers though I have no idea how well it works. It's been in the drivers for a while now but I haven't been able to test it since my PC never runs widowed mode games smoothly so even G-sync can't fix it.

[Trip]

I know this post is a bit old but I believe windows its compositor automatically enables vsync but it does so in a way where it uses its own buffer which it periodically grabs from the gpu. That way the gpu can run at whatever speed it wants to in its own buffer and windows takes care of the vsync timing. I also don't think windows waits for the last frame but just grabs the next frame once it has swapped buffers and leaves it there for the next refresh as I always felt windowed games had slightly more delay. This is in a sense a very clunky triple buffering principle where there is no latency advantage. I have no idea how nvidia forces gsync on the compositor as they need to time the game window together with the compositor I never really tried it but I can't imagine it works very well unless they worked together with microsoft rewriting part of the compositor so the game window is the one that times the vsync. You could of course terminate the dwm process and force your own gsync implementation but other then that I don't know.
http://answers.microsoft.com/en-us/wind ... ccc?auth=1
https://www.reddit.com/r/Windows10/comm ... ced_vsync/

[RealNC]

You are correct. This is how desktop composition works, and needs to work. It needs to grab the output of all applications and present the combined result along with the various desktop effects. The only way to achieve that is to use an off-screen buffer where every drawing operation is redirected to.

This would be a good triple buffering system (giving vsync with low latency.) However, the compositor needs to apply various effects on top of the result, so it can't just present the latest frame from the off-screen buffer. It does additional buffering for its own drawing operations, which adds two additional buffered frames (the drawing operations for the desktop effects are double buffered to avoid flickering). So you get more latency. So in the end, you get 2 more frames of latency overall than you would with normal double buffered vsync in exclusive fullscreen mode.

I have no idea how desktop gsync solves the issue. My guess would be nvidia somehow taps into the actual front buffer and syncs to that.