Tearing happens when your graphics card finishes rendering a new frame while your monitor is already halfway through displaying the previous one. The result is a visible horizontal split where the top half shows one frame and the bottom half shows another, often noticeable during fast camera pans or scrolling.
This occurs because monitors refresh at a fixed rate (typically 60 Hz) regardless of how quickly your graphics card produces frames. If your card outputs 100 frames per second on a 60 Hz monitor, some frames arrive mid-refresh cycle. Without synchronisation, the monitor mixes two frames in a single display cycle.
Real-world example: You're flying a fighter jet in a fast-paced game and turn the camera sharply. Instead of a smooth pan, you see a jagged horizontal line split the cockpit in half for a split second.
How to prevent it: Use vertical sync (V-Sync) to lock your frame rate to your monitor's refresh rate, or upgrade to a monitor with adaptive refresh technology like FreeSync or G-Sync. These technologies vary the monitor's refresh rate to match your card's output, eliminating the mismatch entirely.
When buying a monitor for gaming, check whether it supports your graphics card's adaptive refresh standard and whether the panel refresh rate (60 Hz, 144 Hz, etc.) suits the games you play. Higher refresh rates reduce tearing severity even without adaptive tech, though enabling synchronisation gives the smoothest experience.