If you are using 3D apps or games, you might have come across a strange option in the video settings. It’s usually called “vertical sync” or “VSync” for short, and it’s not immediately obvious what it does. So why is this option here and what does it do? What forms does it take? Here we explain what VSync is and whether you should enable or disable it.
What does VSync do
To get started, let’s take a look at how graphics are processed on your computer. Your computer or laptop has a way of rendering graphics on a screen. These can be graphics built into your processor or an independent graphics card. The main job of the GPU is to “paint” visuals on the screen. The reason you may be reading this article is because of a graphics processor organizing the pixels on your screen.
When you ask your GPU to render a 3D scene, it processes the complete drawings, or “frames,” as quickly as possible. It then gives these images to the monitor for processing. The result is a slideshow-like effect of fast-firing images that gives the appearance of animation, like a flipbook. The speed at which the graphics processor can produce images is called “frames per second”, or FPS for short. The more images your GPU can produce, the smoother your games will be.
Your screen always tries to keep up with the images produced by your GPU. The maximum number of images it can display is shown in its refresh rate, which is usually set in frequency or “Hz”. The ratio is 1: 1, so a 60Hz monitor can display up to 60 frames per second. The refresh rate is shown in a product list like the following picture.
When they are in conflict
Problems start when your GPU starts outputting more frames than your monitor can handle, such as 100 frames per second on a 60Hz monitor. Your monitor may have trouble keeping up with the flow and get out of sync between two images. This is called “screen tear”, where an image appears to be “cut in half”.
This is where VSync comes in. VSync aims to match GPU images with monitor refresh rate to resolve timing issues. This is usually done by freezing the game engine or buffering the frames until the monitor is ready to output the next frame.
Benefits of VSync
As stated, VSync is worth a try if you are experiencing screen tears. This will bring your GPU back to the same level as your monitor and allow them to perform better in unison, thus eliminating screen tearing when done right.
This can also be useful in applications (like very old games) where your GPU significantly dominates graphics demand. Since graphics processors go as fast as possible, rendering old scenes can result in extremely high frame rates. This can cause your GPU to overheat, as it produces images at an incredibly fast speed. Enabling VSync will limit the FPS to monitor refresh rate and stop excessive pressure on the GPU.
Disadvantages of VSync
Since VSync makes frames wait when the monitor is ready, this can cause problems. You may find that your inputs, such as key presses and mouse clicks, are slightly delayed. This can be fatal in games that require reflexes and instant reactions to play. Some technologies have been developed for VSync to help reduce this lag, but it’s worth keeping in mind if you enable VSync and notice your actions are less responsive than before.
VSync is excellent when the frame rate exceeds the refresh rate of the monitor. However, if you get to a graphically intense moment and the frame rate drops below the refresh rate, the graphics card will lower it further to best match monitor preferences. The result is an even greater drop in frame rate during intense moments. Technologies like triple buffering can help prevent this, but it may not be an option that everyone has access to.
The two main types of VSync
The descriptions above refer to the default VSync feature which has been around for years on PC. However, more recently, the hardware powerhouses of the gaming industry have started to come up with new and improved forms of VSync that negate some of these issues. Here’s what you need to know about them.
This revolutionary technology came out a few years ago and does the ingenious job of matching your monitor’s refresh rate to your gaming frame rate. The result is a completely smooth gaming experience (if your GPU can handle it). , that is), without the screen tearing, stuttering, latency, or sharp FPS drops that come with standard VSync. The catch is, you need a G-Sync compatible monitor and Nvidia GPU to use it.
If you want to learn more about G-Sync, we’ve written a full article about it here.
This is AMD’s direct response to Nvidia G-Sync. While the results are great, you will need a FreeSync compatible monitor and an AMD GPU to enjoy FreeSync.
Should I turn it on or off?
So, should you turn VSync on or off? As you can see, it depends on your use case. In general, if your GPU is rendering more images than the monitor can display, it can cause excessive heat and screen tearing. Try enabling VSync through software or your GPU settings to calm things down.
However, if the frame rate is lower than your monitor’s refresh rate, there is no reason to turn it on. There is no tearing or overprocessing to correct, so the only effect VSync will have is potentially to worsen your frame rate and cause input lag. In this case, it is better not to do it.
When used correctly, VSync can help troubleshoot issues and prevent your GPU from running red. When used incorrectly, it can unnecessarily damage your FPS and cause input lag to no benefit. You now know what VSync does and when to activate it.
Now that you’ve figured out VSync, how about trying to overclock your GPU? Also check out our guides on disabling your PC, the best gaming laptops in 2021, and the number of processor cores vs. clock speed.
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