VSync, short for Vertical Synchronization, is a display technology used to synchronize the frame rate output of a computer's graphics card with the refresh rate of the monitor. Its main purpose is to prevent screen tearing, a visual artifact where parts of multiple frames are displayed on the screen simultaneously, causing a split or misaligned image
How VSync Works
When VSync is enabled, the graphics card waits for the monitor to finish its current refresh cycle before sending a new frame. This synchronization ensures that only complete frames are displayed at once, eliminating screen tearing
. Without VSync, the GPU might send frames faster than the monitor can display them, resulting in tearing where the top part of the screen shows one frame and the bottom part another
Benefits of VSync
- Eliminates distracting screen tearing, making games and videos look smoother and more visually appealing
- Helps maintain a consistent frame rate aligned with the monitor's refresh rate, improving visual stability
Drawbacks of VSync
- Introduces input lag, which is a delay between user input (like mouse movement or key presses) and the corresponding action appearing on screen. This happens because the GPU waits for the monitor's refresh cycle before sending frames, effectively putting the GPU one frame behind
- Can cause stuttering if the GPU cannot maintain a frame rate equal to the monitor's refresh rate. This happens because frames might be repeated or skipped to keep synchronization, leading to choppy gameplay
- May unnecessarily cap frame rates on powerful systems or in graphically intense moments, potentially reducing performance
When to Use VSync
VSync is useful if you experience noticeable screen tearing during gaming or video playback. However, for fast-paced games where input responsiveness is critical (like first-person shooters), some players prefer to disable VSync to avoid input lag
. In summary, VSync is a technology designed to improve visual quality by synchronizing frame output with the monitor's refresh rate to prevent screen tearing, but it can introduce input lag and stuttering depending on system performance and game demands
