Windows 10: Disable V-sync for specific windowed applications DWM

My Windows 10 version is 1909 build 18363.1082.


So there is a game that I want to run in windowed mode so I can put other things over it not exclusive fullscreen, dll injection for overlays is not an option.

And there is the mandatory Desktop Window Manager that forces vertical synchronization on every desktop window it renders.

Vertical sync adds a sensible amount of input lag, so is there a way to somehow run an application around the DWM, but not in exclusive full screen? Or is there an opportunity to somehow ask the DWM to not enable vsync on my window?…


Things I tried so far:

Disabled vsync in game's settings for starters;

Set compatibility flags: ~ DISABLEDWM DISABLEDXMAXIMIZEDWINDOWEDMODE for all users

Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\AppCompatFlags\Layers;

Since it is a Steam game, tried running Steam with these compatibility flags as well;

Set Nvidia driver options both globally and for the particular application to not use vertical sync.


Specs:
Xeon E3-1270 V2

GeForce GTX 1070

16 GB RAM

The system is running from a SATA3 SSD.

:)

 

Get better Game Performance under Vista by disabling DWM on a per-application basis!

I just came across this tip/tweak, which probably many who are familiar with Vista already know... It's about disabling the aero effect on a per-application basis, so that you get vista basic interface during gameplay (when you're not going to see it) and it switches back to aero when you exit the game.

DWM, or the Desktop Window Manager, turns the graphics card into a shared resource which allows for the Aeroglass effects and the tear-free desktop. When running normal applications, this is a good thing because it offloads the graphics work (the bulk of which was handled by the CPU in Windows XP) to the GPU, which, when running normal applications is sitting in your computer doing nothing. With Aeroglass/DWM on, the CPU is freed up for other duties as all of the desktop graphics are now handled by the GPU.

In DirectX 9 and OpenGL games however, having Aeroglass/DWM on can decrease performance. This is for a number of reasons :
1.DWM makes the video card a shared resource. When DWM is on, programs are not allowed direct access to the video card.
2.DWM uses both System RAM and VRAM because it maintains an offscreen buffer for every window.

Fortunately, Microsoft has provided a way to disable DWM on a per-application basis so you can still enjoy Aeroglass when not running games. To disable DWM on a per-application basis, right click on the application/game's icon and select properties. Navigate to the compatibility tab, then find and check Disable Desktop Compositing. Now, whenever you launch that program, Windows Vista will temporarily switch back to the Windows XP style graphics subsystem.

DirectX 10 games shouldn't be affected as much (if at all) by having DWM on because the DirectX 10 API is designed around having the GPU as a shared resource and is better able to handle GPU multitasking.

With a few simple steps, on most setups, you can easily make your games run as fast or faster than in Windows XP under Windows Vista.

This will work on both the 32-bit and 64-bit versions of Windows Vista.

 

disabling dwm access denied

I don't know if it is even possible to disable DWM and still have Windows working normally but I found a list of solutions that can solve problems related to DWM:

How to fix Desktop Window Manager notification issues in Windows 10

 

How to always allow administrator permissions for a specific application

Hi Lyon,

Windows 10 gives users the ability to customize how they run applications. We suggest that you follow the steps below on how to grant administrator permission to a specific application:

• Click the Windows icon on your Windows 10 screen that will open the list of applications. Right click on the specific application that you wish to have an admin permission, click the
  More and click Open file location.
• A new window will open to the location of the program. Right-click on the program and click
  Properties from the pop-up menu.
• In the Properties window, click the Shortcut tab and then click
  Advanced.
• In the Advanced Properties window, check the box next to
  Run as administrator and click OK.
  
• The program will now open in administrator mode when you click the shortcut from the Start menu. Repeat the steps above for other desired applications.

Let us know if you need further assistance.