Why is windowed performance so much worse than fullscreen?

[AI-team]

When I'm playing in fullscreen and I have V-Sync enabled, I constantly get 60 FPS, whereas in windowed mode my FPS drops down to ~20 and the game becomes absolutely unplayable. I've made some reasearch on whether this problem might be caused by SDL, but couldn't find anything related to it.

I'm running Windows 7 Pro 64bit with the latest video card drivers.

[Light]

When I'm playing in fullscreen and I have V-Sync enabled, I constantly get 60 FPS, whereas in windowed mode my FPS drops down to ~20 and the game becomes absolutely unplayable. I've made some reasearch on whether this problem might be caused by SDL, but couldn't find anything related to it.

I'm running Windows 7 Pro 64bit with the latest video card drivers.

I'm pretty sure it's a vsync issue. I use vsync with fullscreen so it don't act up, but windowed sucks. Windowed can run without vsync just fine, but then I have the problems in fullscreen.

Mine don't get as bad as you're talking about though. Mine is still very playable, with my FPS in the 40's or 50's.

// edit:
I guess it could help to note that I'm a Linux user. Using Nvidia on an amd64 system.

[Light]

Nope .. I lied. I'm gettin 58-60 FPS in windowed. I guess it was only when I was on Ubuntu. Idk lol

I haven't played in windowed mode forever, so I wasn't 100% sure.

[AI-team]

Yeah when I turn V-Sync off, my FPS almost stays the same.

I know that games usually have less FPS in windowed mode, but a performance-loss of 60% seems to be weird

[Clutch]

Really? In some games like Skyrim I get more FPS in windowed. But likewise I get less FPS in windowed playing tron

[Jonathan]

In some games like Skyrim I get more FPS in windowed.

Same resolution?

[Clutch]

I assume so, since I don't change anything. Unless it forces it to change resolutions when I set it to windowed

[delinquent]

When you run arma does the theme switch to "basic"?

[AI-team]

nope

[delinquent]

Do it manually. On win7 there's issues with aero, or whatever it's called in win7.

[dlh]

I noticed a performance regression in windowed mode when I upgraded to OS X 10.8. Investigating it is on my TODO list (and now I can once again build the game on OS X…).

[AI-team]

Do it manually. On win7 there's issues with aero, or whatever it's called in win7.

Sweet! Disabling Aero did indeed fix the problem, thanks a lot

[Phytotron]

Don't know if it's of any relevance, but back when I was still using Mac, using ATI Displays to activate vsync with Arma: Fullscreen, the FPS would of course be locked to the refresh rate, but when windowed it apparently stopped using vsync and the FPS would jump up to 100+ or whatever.

On Ubuntu, which apparently automatically applies vsync (I've never done anything to activate it, in Linux or in the game), windowed and fullscreen are the same.

Although, the Linux version has some annoying periodic jittering that doesn't occur under Win7; unrelated, I'm sure.

[/dev/null]

Its a common issue on nix systems, I have no idea why. It was supposedly related to compositing, but it rears its ugly head even on systems with no compositing now.

[delinquent]

In a window, the program is subject to limitations placed on it by other programs. This is an issue across all games, across all systems. Plus, the definition of "program" here is not limited to a window with some stuff in it. Even a running DLL in windows can cause an fps drop in other programs.