High cpu with Desktop Window Manager

[Onion Union]

So Wallpaper Engine claims to not use much resources, but whenever I run a wallpaper, lets say a video, wallpaper engine has 0.2% usage but my DWM.exe (Desktop Window manager) jumps from 0.5% to 11% !

Here is a picture with wallpaper engine paused: https://imgur.com/a/5UANk

Here is a picture with the wallpaper running: https://imgur.com/a/dPuAQ


Thanks in advance!

P.s.: DWM.exe can also have high cpu with malware, but there is a slight chance of it being malware in this case, I have ran multiple anti virus softwares and have done nothing suspicious the last few weeks. It only happens with wallpaper engine. If I quit wallpaper engine DWM.exe goes to 0%!
Wallpaper engine itself goes to 0.5% when running.

[Biohazard]

This likely means for some reason your DWM is incapable of composing the desktop on the GPU. One cause I know about is enabling the iGPU in your BIOS and connecting a monitor to it along with having a dedicated GPU installed.

How many monitors are you using and which graphics card etc? Could it be another incompatiblity with something else that is installed and running at the same time?

[Onion Union]

Biohazard の投稿を引用：

This likely means for some reason your DWM is incapable of composing the desktop on the GPU. One cause I know about is enabling the iGPU in your BIOS and connecting a monitor to it along with having a dedicated GPU installed.

How many monitors are you using and which graphics card etc? Could it be another incompatiblity with something else that is installed and running at the same time?

I already have my iGpu connected, I have a gtx 1060 fully updated. I have a wallpaper on both displays.
(Thanks for being active)

[Onion Union]

Biohazard の投稿を引用：

This likely means for some reason your DWM is incapable of composing the desktop on the GPU. One cause I know about is enabling the iGPU in your BIOS and connecting a monitor to it along with having a dedicated GPU installed.

How many monitors are you using and which graphics card etc? Could it be another incompatiblity with something else that is installed and running at the same time?

Extra info:
i5 4690k 4.0GHz
gtx 1060 and iGPU enabled. (and updated)
Main monitor (1080p) connected to my gpu.
Second monitor (4:3, 1280x1024) connected to my igpu.
Again pretty sure there is no malware.

I checked again and the usage goes down within 4 seconds to 4% and 2 more seconds and it 0.5% when I close (edit: pause) the program.

[Biohazard]

Sounds like exactly the scenario I was describing, are you able to connect the monitor from the iGPU to the dedicated GPU instead?

The desktop is a shared window between both GPUs, but they are independent hardware. So what happens is that DWM has to copy the rendered image from one GPU to the other, using the CPU and RAM, hardware acceleration becomes impossible.

[Onion Union]

Biohazard の投稿を引用：

Sounds like exactly the scenario I was describing, are you able to connect the monitor from the iGPU to the dedicated GPU instead?

The desktop is a shared window between both GPUs, but they are independent hardware. So what happens is that DWM has to copy the rendered image from one GPU to the other, using the CPU and RAM, hardware acceleration becomes impossible.

Connecting my second monitor to my gpu is not posseble but I disabled the walppaper on my second display and it seems to go down but it is still ~3% way lower but still pretty high for DWM.exe. Tho I would like a wallpaper on my second monitor, it is not worth the extra usage.

Thanks for the help. Interesting 'problem' aswell.

(And should the usage not go down when a program is maximazed (The option to pause is enabled))

[Biohazard]

When it is paused the DWM usage should go down, does that not happen?

Are you sure that the wallpaper is paused/which wallpaper did you test?

I don't know if there is another issue with pausing with such a setup, but in theory, Windows should be smart enough to stop refreshing the desktop window when the wallpaper stops refreshing too.

[Onion Union]

Biohazard の投稿を引用：

When it is paused the DWM usage should go down, does that not happen?

Are you sure that the wallpaper is paused/which wallpaper did you test?

I don't know if there is another issue with pausing with such a setup, but in theory, Windows should be smart enough to stop refreshing the desktop window when the wallpaper stops refreshing too.

It does go down, when I pause everything, but it doesnt go down when a program is maximized on the second monitor. Btw, I mean only the second monitor, the first one is still playing.

[Biohazard]

Which GPU is the program currently assigned to? I'm not sure if you can even decide that or if Windows enforces it. You can control this on laptops in the Nvidia Control Panel, but iirc on desktops with both dGPU and iGPU running you cannot.

I think you will get the biggest issues with DWM when you display the wallpaper on monitor A although it is being rendered by the GPU connected to monitor B, if that makes sense? You can set the pause option to 'pause all monitors' to mitigate it probably.

[Onion Union]

Biohazard の投稿を引用：

Which GPU is the program currently assigned to? I'm not sure if you can even decide that or if Windows enforces it. You can control this on laptops in the Nvidia Control Panel, but iirc on desktops with both dGPU and iGPU running you cannot.

I think you will get the biggest issues with DWM when you display the wallpaper on monitor A although it is being rendered by the GPU connected to monitor B, if that makes sense? You can set the pause option to 'pause all monitors' to mitigate it probably.

Well I have a desktop pc and see no option to do that is Nvidia control panel. I tried running games on my sec monitor but I have no clue on what gpu it is running. I see no changes i usage of dwm. I can see the video is paused (because of translucant taskbar) but it doesnt change the usage of dwm. I suppose because it still has to render an image?(Eventhough its the same one?). I am in bed so I cannot try this right now (pause all monitors) but I did try 2 different videos with no change if that can help.

I'll try the pause option tomorrow.

Thanks in advance.

[Biohazard]

Okay, try pausing all the wallpapers with that option and maybe try using a stock 3D wallpaper too. If it still causes your DWM usage to increase, then Windows is likely not smart enough to stop updating the deskop window.

You could use the 'stop' option too - it would destroy the wallpaper window - but that would also remove the wallpaper instead of pausing it.

[Onion Union]

Biohazard の投稿を引用：

Okay, try pausing all the wallpapers with that option and maybe try using a stock 3D wallpaper too. If it still causes your DWM usage to increase, then Windows is likely not smart enough to stop updating the deskop window.

You could use the 'stop' option too - it would destroy the wallpaper window - but that would also remove the wallpaper instead of pausing it.

Okay, I'll try it tomorrow. I'll keep you in touch.

[Onion Union]

Biohazard の投稿を引用：

Okay, try pausing all the wallpapers with that option and maybe try using a stock 3D wallpaper too. If it still causes your DWM usage to increase, then Windows is likely not smart enough to stop updating the deskop window.

You could use the 'stop' option too - it would destroy the wallpaper window - but that would also remove the wallpaper instead of pausing it.

So I tried again today and it's seems to be unresponsive. Sometimes it pauses the second screen sometimes it does not. I can see this because of my translucant taskbar.
Very strange, don't know if it's a bug or not.

It also happens with pause all, but the main monitor does pause.

I just disabled the video on my second monitor, but I do not think this is meant to happen.

[Biohazard]

It is supposed to stay paused, yes. Which games did you try it with? Does it even not pause with i.e. Chrome fullscreen (if you are using Chrome)?

[Onion Union]

Biohazard の投稿を引用：

It is supposed to stay paused, yes. Which games did you try it with? Does it even not pause with i.e. Chrome fullscreen (if you are using Chrome)?

Its pretty random (but allot actually) for when it pauses, I'd say 33% of it not pausing. I have no Idea what the cause is. It happended equaly for each I am going to list: Chrome, Chrome with youtube video fullscreen, firefox, firefox fullscreen, cs-go, team fortress 2, gmod, overwatch, skype, steam (steam had the most chance of not pausing), rainmeter.

I tried each program around 20 times, so it was extensive work haha. (Rainmeter and gmod where around 10 tests, because gmod takes a long time to load with mods and rainmeter was only tested while customizing my desktop.)

And DWM.exe usage is out of the roof on the second monitor while testing
Something extra to note: When the monitor did pause DWM.exe usage sometimes went up to 34% and causes the video on the monitor (1 and 2) to "chop". I could see this because of translucent taskbar.

Edit: All games (tf2, cs-go, gmod, overwatch) where fullscreen not borderless window)

[Onion Union]

*bump*