Is there a difference between running games in Windowed or Fullscreen mode?

Solution 1:

Depends on the resolution you play at. If your game resolution is your desktop resolution, then fullscreen is likely to be slightly faster than windowed mode in all scenarios, for the reasons enumerated by Philipp.

Honestly, however, on my dated hardware I take a much greater performance hit by running games at desktop resolution than I do by playing at a lower resolution through the window manager. If your desktop resolution is not your game resolution, by all means do play in windowed mode.

Fullscreen mode at non-native resolution means that instead of shifting graphics output to a rectangle on the screen (something relatively fast), your computer instead has to scale the picture from the game resolution to your native resolution with bicubic filtering or better (expensive!).

Even if it is your monitor itself that does the heavy lifting, or if you disabled hardware scaling at higher resolutions (in which case you still have to translate pixel coordinates), you will get terrible performance and occasionally crashes whenever you Alt-Tab from and to the game.

Finally, not all operative systems allow you to skip the screen compositing system altogether. A notable exception is certainly Ubuntu (which can draw notifyOSD notifications on top of games); I don't know how Macs work here.

So, if getting every single last drop of framerate is your priority here, only play in fullscreen mode:

• If you're using Windows (or Mac?), and
• If you're playing at your screen's native resolution, and
• If you can't get a speedup by playing at lower resolutions in a window, and
• If your desktop is set at your screen's native resolution.

Solution 2:

When an application runs in fullscreen mode, it runs in "exclusive mode". That means it has full and direct control over the screen output.

But when it runs in window mode, it needs to send its output to the window manager (windows explorer) which then manages where on the screen that output is drawn. This takes some additional performance. The performance penalty, however, is greatly reduced in newer version of windows.

Solution 3:

I'd like to make a quick addendum that could be useful for some players reading this topic: when recording gameplay, most applications can not retrieve frames from many games that are running in fullscreen mode. Using windowed or windowed-fullscreen modes will usually provide full access to those frames, and is many times required for best results.

Solution 4:

To add to the other answers, in case of games like Oblivion, Fallout 3, Fallout: New Vegas and Skyrim, running in Windowed mode could help make the game more stable (prevent crashes) and reduce stuttering. Games like these also usually have issues with alt-tabbing, so running in Windowed mode will help.

Mods have been created to run these games in "Fake Fullscreen mode" (actually runs the game in Windowed mode, but makes it appear that it is fullscreen), e.g:

• Fake Fullscreen Mode Windowed - Alt Tab Fix (Oblivion)
• Fake Fullscreen Mode Windowed - Alt Tab Fix (Fallout 3 / Fallout: New Vegas)
• Searching for 'Windowed' in Skyrim Nexus results in a bunch of mods that allow this for Skyrim

Also, from this question: How to force Maximized Fullscreen mode in any game?

I have seen several games that have a video display mode that is windowed with no borders, at the same resolution as the desktop. It's sometimes called "Borderless Windowed" mode, or "Maximized Fullscreen" mode. It seems to balance the trade-off between running in fullscreen, and running a game in windowed mode.

Fullscreen vs Windowed

A game in fullscreen mode fills your screen and is more immersive. Supposedly fullscreen mode provides better performance, but I don't anything about that (nor have I recently observed better performance in fullscreen mode). The most common caveat is that your computer chokes momentarily if you alt-tab to go do something else. Playing in windowed mode allows you to switch to other tasks with no delay, or even multitask. Windowed mode also seems to be better for users using dual displays.

In Maximized Fullscreen mode, the game is in windowed mode, but the borders and title bar are removed and the resolution matches your desktop's. In effect, it looks like you're playing in fullscreen mode, but you can still switch to other applications with no delay. Sounds like the best of both worlds to me!

Multitasking is great if I happen to be respawning, waiting for a loading screen, or if I need to look up information about the game (like looking up quest info for MMOs). Clicking on the game pushes the other (naughty, immersion breaking) windows and the taskbar into the background, seamlessly filling the full screen.

Unfortunately most games don't seem to include this feature yet.