Understanding Screen Tearing
Screen tearing is a visual artifact in video display where a display device shows information from multiple frames in a single screen draw. The artifact occurs when the video feed to the device is not in sync with the display's refresh rate.
The Cause of the Tear
Imagine your monitor draws the screen from top to bottom. If your GPU finishes rendering a new frame while the monitor is halfway through drawing the old one, the monitor will switch to drawing the new frame for the bottom half of the screen. Because the camera or objects in the game have moved between those two frames, the top half and bottom half of the image will not align perfectly, creating a horizontal "tear."
How to Eliminate Tearing
There are several technologies designed to eliminate this annoying artifact:
- VSync (Vertical Sync): The oldest solution. It forces the GPU to hold the frame until the monitor is ready to start a new refresh cycle. While it eliminates tearing, it can introduce noticeable input lag and cause stuttering if your FPS drops below your monitor's refresh rate.
- G-Sync (NVIDIA) & FreeSync (AMD): These are Variable Refresh Rate (VRR) technologies. Instead of forcing the GPU to wait for the monitor, they force the monitor to wait for the GPU. The monitor dynamically changes its Refresh Rate (Hz) on the fly to match the exact FPS being output by the GPU. This eliminates tearing without the severe input lag penalty of VSync.
- Fast Sync / Enhanced Sync: These technologies allow the GPU to render as fast as possible (reducing input lag) but only send the most recently completed frame to the monitor when it's ready to refresh, dropping the excess frames.
Testing Your Setup
If you have a G-Sync or FreeSync monitor, ensure the feature is enabled in your GPU control panel and in the monitor's physical OSD (On-Screen Display) menu. Run the test above. If the bar moves smoothly without breaking, your VRR technology is working correctly.