This is James here from Canada, As I have seen your comments above & I think it is an unfortunate fact of computer graphics that if you disable VSync, your graphics card and monitor will go out of synch. Whenever your FPS exceeds the refresh rate (e.g. 120 FPS on a 60Hz screen), or in general at any point during which your graphics card is working faster than your monitor, the graphics card produces more frames in the frame buffer than the monitor can actually display at any one time, so the end result is that when the monitor goes to get a new frame from the primary buffer of the graphics card during VBI, the frame may be made up of two or more different frames overlapping each other. This results in the onscreen image appearing to be slightly out of alignment or 'torn' in parts whenever there is any movement - and thus it is referred to as Tearing.
The precise visual impact of tearing differs depending on just how much your graphics card and monitor go out of sync, but usually the higher your FPS and/or the faster your movements are in a game, such as rapidly turning around, the more noticeable it becomes. This is because the contents of the overlapping portions of new and old frames are more noticeably different from each other in such cases.
Tearing does absolutely no damage to your graphics card or monitor. It just highlights the physical limitation of your monitor in keeping up with the graphics card when the two aren't synchronized. In the example of 120FPS on a 60Hz monitor, at most only 60 whole frames can actually be refreshed during any one second by your monitor, so the other 60 frames your graphics card is producing are pretty much being wasted and are coming out as lots of partially overlapping frames and hence only contribute to tearing. So even if you don't want to enable VSync, it makes sense for you to raise your in-game graphics settings to reduce your FPS such that it stays closer to your refresh rate. This will help you get more whole frames and thus reduce tearing. It may seem cool to have a very high framerate, but as you can see it is wasteful and only causes graphical glitches when VSync is disabled.