Vertical sync or Vsync is one of the most cryptic graphical settings in a video game, seeing as most of them don’t really explain what it does. Those that do merely say it’s there to reduce screen tearing, but this doesn’t exactly answer ‘What is VSync?’
You’ve come to the right place. We’re slightly less confused than you are, but VSync does a lot more than what its tooltip prompt says. So the answer to the question ‘What is VSync?’ is more complex as there are lots of layers underneath the notion that need peeling.
So, What Is VSync?
To understand it, we need to first explain how your monitor displays all the information thrown at it by the GPU (graphics processing unit) or graphics card and the application it’s running.
A gauge of a video game’s performance is through frame rate or FPS (frames per second). Higher frame rates are better and feel smoother or more responsive since there are more visual animation frames to display.
However, the frame rate your GPU is capable of for every specific game is gated by your monitor’s refresh rate or frequency which is usually displayed on the monitor spec sheet as:
- 60 Hz (Hertz)
- 144 Hz
- Or even 240 Hz
A 60 Hz monitor can only display a frame rate of 60 FPS, a 144 Hz monitor can display a max of 144 FPS, and so on.
Additional framerates are wasted since you won’t see them even if the frame rate counter displays them. That’s why monitors or displays with higher refresh rates are more expensive. More frames displayed means a smoother animation that feels less like a slideshow.
So for example, you’re playing League of Legends and the frame rate counter states ‘200 FPS’ but your monitor only has 144 Hz. You’re only going to see and feel 144 FPS, therefore, the additional 56 FPS is going to go to waste and is just making your computer (particularly the GPU) generate excess heat.
This is where the ‘screen tearing’ issue also occurs.
Excess Frame Rate Causes Screen Tearing
Now, because your monitor is only capable of displaying 144 FPS (for example) and League of Legends is running at 200+ FPS, your monitor will experience trouble allocating those excess frames in the screen, especially if there are so many.
Hence, screen tearing will happen, and you can refer to the image above to get an idea of what it looks like. This kind of tearing is also more visible during fast movements.
Some gamers or some games are a lot less sensitive to it, particularly strategy titles. However, when you need to keep turning and changing your view in fast, jerky movements, it’s a lot easier to spot screen tearing during high frame rates.
VSync Caps Your Frame Rate & Synchronizes It With Your Monitor
Here’s where VSync comes in.
If you turn the setting on in the graphics section, VSync in the application will synchronize the frame rate to that of your monitor’s refresh rate so that they’re capped at the same number.
This way, the screen tearing is eliminated and you’ll be able to see a clearer image since the frames are no longer getting spliced together too fast for the monitor’s speed or frequency.
It’s a marvelous graphical setting which, due to the improvement it brings, should have been mandatory, except it’s optional. So why exactly is VSync not turned on only by default (usually)?
The Drawbacks of VSync
Just as Vsync brings benefits to image quality, it also brings its own slew of disadvantages which can be a dealbreaker for a lot of people, particularly those who prefer fast games.
Since VSync caps the FPS depending on the monitor’s refresh rate or frequency, you’d be getting lower numbers and less smooth performance.
Because while the monitor can only display frames up to a certain number before tearing occurs, the responsiveness you feel between say, 120+ FPS and a VSync-capped 60 FPS is dramatically different and smoother, even if the monitor is struggling to keep up.
This is where the biggest disadvantage of using traditional or default VSync is most palpable.
VSync Causes Lag
Apart from the obvious lower maximum frame rate, VSync’s other disadvantageous effect is the input lag or latency it introduces.
To make this simpler, think of your monitor and your GPU as partners in a duo sack race.
The GPU is the faster one while your monitor is the slower one. The sack is Vsync. If the GPU jumps or moves too fast, the monitor can’t keep up, so the sack (VSync) will act as a limiter to what the GPU is capable of. Doing so will make the GPU wait for the monitor which is now gasping for air in the race.
Because of this, the GPU will now have to delay its actions in the sack race. So now, their movement is laggy and late.
In gaming, this translates to lag, stuttering, and dropped inputs (mouse or keyboard presses getting ignored if they’re performed too fast). That’s because the VSync is causing this latency so that the monitor can keep up with the fast GPU.
This kind of interaction can feel sluggish in-game though you’ll only spot the difference if you look for it and if you keep turning VSync on and off to compare.
You can probably tell how much of a disadvantage this is for competitive shooters. Lag of any kind is always frowned upon in such serious video games. Some gamers even opt to just endure the screen tearing to avoid the lag and latency that VSync can cause.
You Don’t Always Need VSync
The good news is that your needing VSync or not depends entirely on your components, particularly your monitor and your GPU, and even the game to a certain extent.
Because screen tearing mostly only happens when the frame rate exceeds the monitor’s refresh rate, it usually won’t appear if the FPS is considerably below. Again, this is why high refresh rate monitors or displays are expensive.
If you have, for example, a monitor with a 240 Hz refresh rate, then you likely won’t even need to enable VSync when playing the latest graphically demanding titles since 100+ FPS on maxed-out settings is already tough to achieve for the average GPU.
It’s a different story when you’re playing older video games such as Counter-Strike: Global Offensive or the aforementioned League of Legends.
Moreover, some video games like Genshin Impact have chosen to limit their frame rates to certain numbers such as 60 FPS regardless of whether VSync is on or off. This could be due to character or action animations being tethered to frame rates or perhaps as a way to synchronize PC gamers with PlayStation or console gamers in the same game (since console games are capped at 60 FPS– sometimes just 30 FPS).
On a final note, if you’re not really playing a competitive video game, there’s no reason to be scared of VSync as visual clarity is still more important for your immersion. We hope that answers your ‘What is VSync’ query, and regardless, we’d love for you to spread the good word by sharing this article.