Desktop Window Manager dwm.exe consumes high CPU or Memory

Desktop Window Manager or dwm.exe in Windows 10 is a system process that is responsible for managing, inter alia, visual effects on the desktop. No doubt the application does require some resources to run however, modern desktops and laptops are provisioned to handle it easily. Let us learn some more about this Windows process.

Desktop Window Manager – dwm.exe

DWM.exe helps with rendering visual effects on the desktop as well as with various features such as glass window frames, 3-D window transition animations, high-resolution support and so on.

Desktop Window Manager helps writes each picture on the Windows to a place in the memory and creates a combined view of all of them on the screen and sends it to the display. This way, the operating system can use Hardware Acceleration to create smooth animations. It could also be used for creating transparent effects.

Desktop Window Manager consumes high CPU or memory

The file which represents the Desktop Window Manager is dwn.exe. It usually occupies 50-100 MB of memory and around 2-3%CPU – but it all depends on your system. If a large number of windows and animated processes are open, it will use high memory, and thus consequently slow down the system or cause freezes. If you face problems with dwm.exe, here are a few things you could try:

1. Disable screensaver
2. Run the Performance Troubleshooter
3. Adjust the system for best performance
4. Switch to the Basic Theme
5. Update display drivers
6. Update all installed software
7. Scan PC with antivirus software
8. Troubleshoot in Clean Boot State
9. Use Xperf.

1] Disable screensaver

If Desktop Window Manager is consuming high resources you need to change your theme or wallpaper and see if that helps. If you have activated a Screensaver, disable it and see. In fact change all your Personalization settings like Lock Screen, Color Profiles, etc, and see if it makes the problem go away.

2] Run the Performance Troubleshooter

You need to optimize Windows for better performance. Run the Performance Troubleshooter. Open an elevated Command Prompt, type the following and hit Enter:

This troubleshooter helps the user adjust settings to improve operating system speed and performance. If this does not help, you may need to troubleshoot Windows performance issues. Check if your version of Windows has thisone.

3] Adjust the system for best performance

You may also search for and open Performance Options window, and click on the Visual Effects tab. Select the radio button to Adjust the system for best performance.

4] Switch to the Basic Theme

Switching to the Basic Theme will greatly reduce the load on the system and the battery. However, it wouldn’t stop the Desktop Window Manager from running.

5] Update display drivers

Some have reported that updating display drivers helped them. So check if you are using the latest device drivers for your computer.

6] Update all installed software

Some installed software are also known to make dwm.exe use high memory. So make sure that your Windows operating system, as well as all your installed software, is updated to the latest versions.

7] Scan PC with antivirus software

The legit dwm.exe process is located in the System32 folder. But if it is located in some other folder, it could well be malware. So do run a full scan with your antivirus software.

8] Troubleshoot in Clean Boot State

Perform a Clean Boot and then try to manually find the offending process which is causing dwm.exe to perform inefficiently.

9] Use Xperf

System administrators can make use of Xperf which is a performance tracing tool based on Event Tracing for Windows, and which is a part of Windows Assessment and Deployment Kit.

How to disable Desktop Window Manager?

Turning off Desktop Window Manager completely wouldn’t make much of a difference, yet if you wish to disable it, you can do so in Windows 7 and earlier as it runs as a Service.

Type services.msc in Start Search and press Enter to open the Services Manager. Locate the Desktop Window Manager Session Manager service and change its Startup type to Disabled.

In Windows 10 it is an application and hence cannot be disabled.

Want to know about these processes, files or file types?

Что такое Desktop Windows Manager (DWM)?

Одно из самых широко рекламируемых преимуществ Windows Vista — новый графический интерфейс Aero (в прошлом Aero Glass), который придает прозрачный, «выбеленный» вид краям окон экранов, окошкам просмотра панели задач и переключения задач. В Aero также задействован новый механизм переключения задач Flip 3D. Как же работают эти функции?

В. Что такое Desktop Windows Manager (DWM)?

О.

DWM функционирует как служба: Desktop Windows Manager Session Service с внутренним именем UxSMS («ux» означает «user experience»), реализована в образе dwm.exe. Эта служба обеспечивает компоновку рабочего стола для всей операционной системы при работе с режимом Aero.

Во всех предыдущих операционных системах (и Vista без Aero), каждое приложение записывает данные непосредственно в буфер экрана. В случае, если окно перемещается над графической областью другого окна, система посылает в приложение сообщение WM_PAINT, чтобы перерисовать окно. Если приложение занято, сообщение WM_PAINT может остаться необработанным, и за перемещаемым окном возникает след на экране. Кроме того, если перемещаемое окно не удается перерисовать достаточно быстро, оно распадается на фрагменты. Это явление называется tearing.

При использовании DWM ситуация меняется. В системе используется внеэкранный буфер для компоновки внеэкранных буферов графического дисплея каждого приложения, затем DWM переписывает данные из этого буфера в экранный буфер. Таким образом, DWM содержит графические данные каждого приложения, и приложению не нужно перерисовывать свое окно при каждом обновлении экрана. Вместо этого для подготовки нового экранного буфера используется моментальный снимок последнего обновления дисплея, полученный из приложения. При работе с медленным приложением следов на экране не возникнет, так как для приложения DWM использует внеэкранный буфер. Следует отметить, что процесс DWM всегда активен, но в основном бездействует, за исключением тех случаев, когда система находится в графическом режиме Aero. Благодаря использованию в DWM отдельного графического буфера для каждого активного приложения, становятся доступны окна просмотра приложений и режим Flip 3D. Существуют даже API для доступа других приложений к технологии окон просмотра. Когда операционной системе необходимо окно просмотра, она просто сжимает графический буфер приложения, предоставляемый DWM.

При работе в любом другом графическом режиме, в том числе Vista Basic, DWM используется мало, и следы от перемещающихся окон по-прежнему заметны. Причина в том, что дисплей — не композитный. Процесс DWM по-прежнему активен даже в режиме, отличном от Aero; он обслуживает Windows Ghosting, процесс, благодаря которому не отвечающее окно принимает белесый вид, а к заголовку окна добавляется запись «(Not Responding)».

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What are Window Managers, Desktop Managers, Desktop Environments, Login Managers? Which one do you need and Why? [duplicate]

What are Window Managers, Desktop Managers, Desktop Environments? Which one do you need and Why?

1 Answer 1

Understanding Dos and Window Managers

Ubuntu and Debian are like DOS; it receives input from the keyboard and responds to input by outputting text to one screen (one window). A window manager (WM) allows multiple windows to be drawn and is thus essential for multitasking and a huge evolution in OS design. Anything drawn on the screen; that’s a window manager at work, but it needs to receive drawing orders from a program or a number of programs. Drawing a background on the desktop (root window) that’s a program that sends orders to the WM (Window Manager). Restoring desktop content that’s another program giving orders to WM. Drawing a taskbar, an application launcher, a dock, a system tray that’s a number of programs giving more orders to WM. When receiving these drawing orders part of those orders must specify whether to draw in an existing window or a new window.

The question is what does the WM do if it’s a new window? Does it put on top of another window, beside it or allow for both possibilities? This is the basic difference between a stacking window manager, a tiling window manager and a dynamic window manager. Microsoft Windows uses a stacking WM, but wait a minute why are the windows allowed to be stacked and where is the order? Two reasons: windows are allowed to be stacked to make the most out of screen real-estate and order is arbitrary and unnecessary for stacking WM; if you can see it and select it then that is sufficient according to Microsoft and stacking WMs. How — is called a task bar. On windows this taskbar holds the start button, quick launch, windows (in order that they are launched) and system tray. So, you should be able to see your windows in the taskbar via its title and simply select it with your mouse to bring it to front and into focus. That’s how stacking WMs work. They technically don’t require a taskbar if they have key bindings (keyboard shortcuts) to navigate the windows. Coincidentally, this is exactly how a person likely navigates windows with a tiling WM which orders the windows according to a schema without overlap at the cost of screen real-estate.

In a tiling WM windows must be selected and maximized each time which is annoying. The joy of stacking WMs is you can navigate through maximized windows; you only have to maximize them once to do this. Perhaps some tiling managers have a way around this, but none that I know of. Now tiling managers have a way around limited screen real estate by using virtual desktops aka workstations; each workstation has its own screen, thus when you run out of screen space you simply move to another workstation. You can also do this with stacking WM, but it is especially important for tiling WM. However, I find this annoying and tedious. If you have an extra large screen or multiple screens tiling managers make more sense, but this is an opinion as many Windows users have multi-monitor setups, and which kind of window manager does Windows use — a stacking one. A layman with a small single monitor will like prefer a stacking window manager with a taskbar and find this easier to use (is merely mouse dependent). This is because tiling WMs use key combinations to control windows and there are a lot of key combinations to remember and a new user especially one unfamiliar with tiling WMs cannot easily figure out how to work it especially when there are no visual cues to help guide them like a minus, rectangle or X at the top right of the window of some stacking WM. A tiling manager is thus innately more complicated for a layman. Key bindings allow one to manipulate windows (minimize, maximize, open, close, make full screen), organize (put side-by-side, put on a different workstation), select windows (switch to, switch from) and execute programs without needing an application launcher, and much much more.

Beyond familiarizing yourself with the difference between different types of window manager there are important considerations prior to selecting your specific WM. Make sure you always install a window manager which has all key and mouse bindings and buttons you require to control windows, and that allows for custom key bindings as well. If there are insufficient key bindings to control windows then that is a shitty WM, don’t install, try, test or use it. N.B. custom key bindings can be enabled with a number of other applications separate from the WM. If you install a stacking window manager, make sure you also install a taskbar. Likewise, I would not recommend a WM that does not come with a config file, because truth be told you are going to have customize the shit out of it especially if you are not using a Desktop Manager and we’ll talk more about that shortly.

Some examples of great stacking window managers include (Blackbox, Openbox, Fluxbox, XFwm, Kwin, Jwm, Icewm, Metacity, Mutter). Mutter is designed as a library. Thus GNOME-Shell is the everything; a shell, a compositor and a window manager [Link ][1]. Some examples of great tiling window managers include i3, Sway, Awesome, Dwm, PaperWM).

Understanding Desktop Managers

Some example of Desktop Managers (DM) include Gnome Desktop, Xfce, LXDE, Plasma (KDE). DMs are a series of programs and their dependents that tell a WM to draw various components of a Desktop. A DM is not a DM unless it has a persistent graphical user-space; what is known as a desktop. A DM should also provide the option to install various widgets on the desktop or taskbar, and ability to add and remove anything on the desktop. All other functions are optional, but they frequently include a taskbar with an app launcher and a system tray. The desktop (user-space) is technically a root window that cannot be closed, but can be killed. This root window is session and reboot persistent and possesses a customizable background, important or frequently accessed files and folders, and shortcuts to access programs, files and folders anywhere on the system i.e, the recycle bin and mounted drives could be on the desktop. Different users have different desktops.

A Desktop Environment (DE) anything on the desktop or initialization of the window manager that is reboot persistent. If you avoid Desktop Managers, and opt to use mostly just a window manager instead, you probably want to enhance your DE, and don’t just want; to arrive at a terminal, blank background or empty wallpaper background with or without a right-click menu.

i3wm is a tiling window manager that comes with a number of programs which is «code» for DE enhancements. Those enhancements are a makeshift taskbar and systemtray. Looking at the underpinnings of a desktop, if you think about it, it is essentially a file manager with one folder and background. That is to say it is a separate program from the window manager. You can set a root window in i3wm and most window managers and even make that reboot persistent, but that falls into DE, not DM because it does not have a userspace nor does it have the builtin ability to easily add or remove items to the desktop.

DMs always use a stacking WM because these WMs allow anything to be drawn anywhere and over anything which is requirement for a desktop, and a desktop is not only a root window, but a fakefullscreen (FFS) root window. FFS fills the screen up to the borders of the other non-transparent windows that are part of the desktop i.e., taskbar.

Now, do you want or need a user-space for your files and folders that is always instantly available on the background and doesn’t require loading a file manager to access your /home directory (true user-space)? If you answer yes then you want a DM which gives a desktop and allows you to customize it easily. Remember, you will also need a stacking window manager, because a tiling window manager must divide windows without overlap with a preset order. A tiling WM like any WM must be consistent with everything, and since tiling WM order windows in accordance to presets, to draw a taskbar would require making an exception, but a preset exception is an oxymoron or impossibility. It essentially falls outside the role of a tiling window manager. A stacking window manager on the other hand does understand the concept of a root window. Both stacking and tiling WM must draw within a window, but because stacking WM can overlap windows in any manner, it effectively means they can draw anywhere without any rules unlike a tiling WM. I have not yet found a tiling WM that understands the concept of a root window, likely this would be a dynamic WM. Remember the primary features of a DM is the desktop (persistent graphical user-space) and the ability to add and remove items from the desktop.

When picking a DM it can confusing, but it isn’t if you remember what they are designed to do; provide a persistent graphical user-space (desktop) and allow the user to easily customize the desktop i.e., easily add or remove items (widgets, bars) from/to it. And third information of interest is memory use. In terms of doing their job, I would rank as follows: 1. Plasma-Desktop (just doesn’t get any better than this), 2. Gnome-Desktop (Not as modular or easy, but still very customizable) 3. XFCE (lacking in ease of adding and removing widgets; items you can put on bars or the desktop). That’s my opinion. On memory, the ranking is 1. XFCE (300MB), 2. Plasma (410-500MB) 3. Gnome (450-500MB).

It is simply a matter of taste. DMs are easier to use and use more memory and cpu. The WM route, requires a lot more work or labor of love to get that polished look and to make it persistent, but moreoften uses fewer system resources and is more stable.