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I have been having a problem with my computer(laptop) when using the Windows 7 Ultimate Basic Theme.
The problem I'm having is that, whenever this theme is active, and I move one window over another, I get this "frame lag". That's as close as I can describe it, here is a screenshot:

enter image description here

The amount of frame of the application that it "lags" onto the underlying application varies. As an example: When I'm using 2 notepad Windows, there's only a tiny bit of frames that get left behind, and when any window is moving over and Explorer window, it's a lot of frames. The "left-behind" frames clear every .8 seconds or so, which also constantly varies between programs.

This only happens on the basic theme. Works fine with Aero. My video card is perfectly capable of rendering this. I can run Crysis just fine. It's an nVidia 9600M GS with 512MB of RAM (M ofcourse meaning "mobility" as it's in a laptop.). I currently aslo have 2 FullHD monitors connected, but it also happens on the native laptop screen with a moderate resolution of 1440 x 900. All the latest nVidia drivers have been installed.

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Weird, I have this problem too and I never noticed it since I use aero. But, I need to do a lot of dragging to make it appear. First the first 2 or 3 seconds, minimal "shadows". Then after 4 or 5 seconds, lots of shadows. Then they disappear. GEforce 9500. I always thought aero was overlaid on top of basic, but maybe it's the other way around. Maybe it has something to do with windows checking to see if you're trying to do the "aero shake" feature where you can minimize everything by shaking the title bar. –  CreeDorofl Apr 3 '11 at 1:42
    
I honestly doubt that. I have also disabled Aero shake. I guess it's an nVidia geForce problem. Interesting. Thanks for your comment :) –  René Apr 3 '11 at 2:46
    
One other thing (you may already know this). Sometimes the latest driver isn't always the absolute best. I've had nvidia cards in the past with specific problems that were fixed with a slightly different (and older) driver. Might be worth a try. –  CreeDorofl Apr 3 '11 at 2:49
    
Yes, I also think that this started happening after a specific diver update a LONG time ago, but I don't feel like going through all of them to check for a fix. Thanks tohugh. It's real hard to search this on Google. Idk what to search for. –  René Apr 3 '11 at 2:59
    
I had the same thing, I tried windows 7 basic theme slow, and windows 7 basic theme problem. Most of the problems were with trying to turn on aero. I did find one guy who said aero was fast but basic was laggy: nvnews.net/vbulletin/showthread.php?t=113751 ...same advice though, try a diff. driver. –  CreeDorofl Apr 3 '11 at 3:08

1 Answer 1

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What you are experiencing is called "window tearing". It's a phenomenon that occurs on Windows Basic theme only, due to the absense of Windows Aero.

Aero uses the DWM (Desktop Window Manager) introduced in Windows Vista, which is much more closely bound to the graphics card and hardware acceleration, compared to using the computer without DWM.

This means that while Aero actually looks better, a much higher percentage of it is rendered by the GPU, and not the CPU. In the Windows Basic theme, much of the screen is software accelerated, by individually sending the WM_PAINT message to all applications.

Now, furthermore, DWM uses double-buffering to prevent flickering and Window tearing.

Wikipedia states:

Since MIL provides a retained mode graphics system by caching the composition trees, the job of repainting and refreshing the screen when windows are moved is handled by DWM and MIL, freeing the application of the responsibility. The background data is already in the composition tree and the off-screen buffers, that is directly used to render the background, without having the background applications to re-render themselves by sending them the WM_PAINT message, as was the case with pre-Vista Windows OSs. DWM uses double-buffered graphics to prevent flickering and tearing during window moves. The compositing engine uses optimizations such as culling to improve performance, as well as not redrawing areas that haven't changed. Because the compositor is multi-monitor aware, the DWM natively supports that too.

Now, my theory of why it is happening is not because of the GPU. It's because of your CPU. If having multiple monitors connected in Windows Basic theme, then depending on your graphics cards performance, using Aero may actually be faster.

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Awesome. My CPU is actually on the low side of preformance. I (believe it or not) have more preformance in games with Aero ENABLED than DISABLED. This explains it. Thanks :) –  René Aug 26 '11 at 19:41

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