Nvidia Reflex

[deama]

Found a video rundown of reflex:

phpBB [video]

Kinda confused, he says that with reflex on, it eliminates (or drastically reduces?) the buffer between the cpu and gpu? But isn't that what ultra low latency on max? By setting the render frame buffer to 0?

deama
2-3 games in which input lag is important and which cannot work in efs. not worth it every time you mention: the need to disable dwm. I think that's exactly what Unixko wanted to say.

I'm not saying to disable it, I'm saying it would be easy for nvidia to bypass it so users wouldn't have to disable it and fiddle with that crap.

[andrelip]

According to the updated version of the Nvidia Frame view, I have 0.370 ms render to present(). So I think that DWM is off.

Setup:
GTX 1080, 9700k, CSGO on benchmark level (1600 fps).
240hz with some reg fixes and disable full-screen optimizations.

But I also remember that a while ago in GPUView, I don't have flip pages showing, and now it has more than 20. So I'm a little bit confused if DWM is active or not.

[1000WATT]

The delay of 0.370 ms does not mean that the application bypasses dwm.

[andrelip]

The delay of 0.370 ms does not mean that the application bypasses DWM.

I believe that the present packet is the last piece of the chain, and the frame is immediately swapped to the front-buffer. So it should count DWM and flip wait chain.

[1000WATT]

andrelip
Perhaps in your specific example, everything happens exactly as you wrote.
Since I don't know what exactly "PLAT" measures 0.370 ms.
But you can find out in which mode the application is running through the PresentMon64-1.3.1 program.
A full description is available at https://github.com/GameTechDev/PresentMon.

In short.
For example, battlefield 1 wddm 2.1.

Game bf1 on a separate line. Hardware: Legacy Flip = Indicates the app took ownership of the screen, and is swapping the displayed surface every frame.

fse.jpg (86.96 KiB) Viewed 5067 times

Game bf1 on a separate line. Composed: Copy with GPU GDI = Indicates the app is windowed, and is copying contents into a surface that's shared with GDI.

windowed.jpg (38.82 KiB) Viewed 5067 times

It looks like this without "DWM composed".

killdwm.jpg (4.56 KiB) Viewed 5067 times

Later versions of wddm have more modes.

[1000WATT]

This is an example . exclusive fullscreen. https://youtu.be/xuJryS7bMHo

This is 100% DWM composed. ... Old Windows 10. FrameView shows ~ 0.30. https://youtu.be/EJ1hgy9HFLw

[diakou]

This is an example . exclusive fullscreen. https://youtu.be/xuJryS7bMHo

This is 100% DWM composed. ... Old Windows 10. FrameView shows ~ 0.30. https://youtu.be/EJ1hgy9HFLw

Do you know what to do about games that have no exclusive fullscreen mode, but when you kill DWM the game lags horrendously? It's most likely due to DWM's v-sync application keeping the game smooth and consistent, but when I mean "horrendously" I don't mean tearing, I mean FPS jumping between 30-50-55 in a 60fps locked game.

The game I play is called Brawlhalla, but turning off DWM on windows 8 or 7 makes the game go absolutely crazy, this sucks because the game has no way of going into exclusive fullscreen and the latency penalty is massive. It's reduced a ton by using a 240hz or 360hz monitor due to how DWM lag works, but it's still not good enough in my opinion. I think the only way is probably using g-sync or freesync methods. (if you could, it's a free game on steam to download, 400mb, try with DWM and DWM off and you'll see what I mean by extreme lag) it also only has copy with gpu gdi available until you shut off DWM, then it's legacy copy to front buffer.

[1000WATT]

I don't think I fully understand what you want.
Sorry, I can't help you measure the delay, I don't have that much free time.
But I tried the game in different modes (60hz, 240hz, g-sync on \ off, vsync on \ off, SS, dwm kill).
And looked at the statistics in CapFrameX. The behavior of the game is quite normal, without a big drop in fps in most modes.
(SS works great.)
https://youtu.be/eG3U6J_7leQ

[diakou]

I don't think I fully understand what you want.
Sorry, I can't help you measure the delay, I don't have that much free time.
But I tried the game in different modes (60hz, 240hz, g-sync on \ off, vsync on \ off, SS, dwm kill).
And looked at the statistics in CapFrameX. The behavior of the game is quite normal, without a big drop in fps in most modes.
(SS works great.)
https://youtu.be/eG3U6J_7leQ

Wow! Everytime I have killed DWM, Brawlhalla goes crazy, unstable frametimes and performs a lot worse than with DWM on. Can you please send me a private message with what you did specifically? Windowed Mode, DWM killed, windows version? I will measure the delay myself, no problem! What did you do for the scanline sync? I would really appreciate if you could send me the details in a private message whenever you have the time available. I just need to replicate the steps you did.
P.S thank you for testing as well!

[1000WATT]

I see no reason for a private message. This might be useful to other users. Offtopic is a frequent occurrence on this forum.
windows 1607, nvidia driver 452.06, nvcp - vsync off, null on, windowed mode.
DWM killed

@echo off
taskkill /IM explorer.exe /f
pssuspend winlogon.exe
taskkill /IM dwm.exe /f
userinit.exe

net framework 4.6

c++.jpg (60.8 KiB) Viewed 4921 times

I didn't configure SS, I just used the value -1 to check how the synchronization works.