Vertical Tearing Question

[impuLsive]

When one gets tearing, It causes a sort off graphical lag, correct? I have a LCD as of right now (Refresh rate: 75) and playing games such as Counter-Strike Source (I get 250+ frames average, and 90-100 in firefights), Ill get real noticeable tearing on some maps and not so noticeable on others. Theres a line that goes from the left side of my screen, to my right hand side of my screen. My main question is: Is tearing supposed to cause this graphical lag, or is it supposed to just have a line drawn on the monitor?

 

[squeezee]

Esentially you are getting the opposite of lag but rather its trying to update as fast as possible. The screen 'tears' because the video card starts displaying a new image while it was in the middle of drawing the previous one on the screen. Its like if you have a book and tear a page in the middle, you see both the current and previous page at once.

If you're getting a framerate of 250fps and the screen can only display 75 unique frames per second its going to be displaying esentially 3 partial images at once. Sometimes it isn't noticable as the differences between the successive images will be small and other times such as when you turn around rapidly the difference between the images will be huge.