What is VSync, and why do you need it?

digitaltrends.com:

If you’ve been playing PC games for a number of years, you’ve probably heard the term ‘VSync’ tossed around once or twice. Maybe you’ve also heard of G-Sync and FreeSync. For those unaware, VSync is actually short for ‘vertical synchronization’. This is a display feature that is designed to keep your gaming screen running in sync with your computer’s GPU. VSync isn’t just important for PC gaming, but it’s one of the most important criteria that goes into a good gaming display.

In this article, we’re going to take a closer look at VSync (and its related technologies) to find out exactly how it works, if you should have it enabled, and how to disable it if you don’t like the optimization.

What is VSync technology?

VSync is a graphics technology designed to sync a game’s frame rate with the refresh rate of a gaming monitor. Originally pioneered by GPU manufacturers, this technology was introduced to address the issue of screen tearing, which occurs when your screen simultaneously presents portions of multiple frames. This can lead to visual artifacts resembling the example shown above, typically manifesting as a horizontal split in the display. Screen tearing arises when the monitor’s refresh rate (the frequency at which it updates per second) is not synchronized with the frames per second being produced by the graphics card.

Screen tearing can occur at any time, though it is most prevalent during fast motion, particularly when a game runs at a higher frame rate than the monitor can handle or when the frame rate changes dramatically and the monitor can’t keep up. It is particularly noticeable during fast-paced games with vertical image elements, such as trees, entrances, or buildings. When this happens, those lines will quite clearly not line up correctly, which can break immersion and make a beautiful game look rather ugly.

VSync does a few things to help alleviate this. First, it