Why Shouldn’t I Use VSync? Understanding the Downsides of Vertical Sync
The allure of a perfectly smooth, tear-free gaming experience often leads gamers to enable VSync (Vertical Synchronization). However, while VSync does achieve this goal, it comes at a cost that many find unacceptable, making it a technology that’s often best left disabled. The core reason you might want to avoid VSync is its tendency to introduce input lag and potentially cause frame rate stuttering, especially when your hardware can’t consistently match your monitor’s refresh rate.
Essentially, VSync forces your graphics card to synchronize its frame output with the refresh rate of your monitor. While this prevents the unsightly screen tearing that occurs when frames are displayed out of order, the method it uses to achieve this synchronization can lead to a less responsive and sometimes less smooth gaming experience. If your computer struggles to consistently push out frames at the monitor’s refresh rate, VSync will lower your frame rate down to a stable division of your refresh rate (often half). This drastic drop in frame rate can result in the perceived stuttering. This is compounded by the input lag, which is especially detrimental in fast-paced and competitive online games, making it feel like there is a delay between your actions and the game’s response.
While VSync’s primary function of preventing screen tearing is valuable, the negative impacts it has on input latency and frame rate fluctuations make it a problematic solution, and one that is typically not worth the tradeoff in today’s tech-saturated market. In short, unless you cannot mitigate tearing with other technologies, the cost of VSync is generally higher than the benefit.
The Problems with VSync
Input Lag
The most cited reason gamers dislike VSync is the input lag. This delay between when you press a button or move your mouse and when that action is reflected on screen can be incredibly frustrating, particularly in games where precision and timing are critical. VSync creates this lag by forcing the GPU to wait for the monitor’s vertical refresh cycle before sending out a new frame. If the GPU finishes rendering a frame early, it has to hold it until the next refresh cycle, causing the delay.
Frame Rate Reduction
When your system cannot maintain the targeted refresh rate, VSync can also lead to significant frame rate drops. Instead of allowing frames to render as quickly as possible, VSync will force the frame rate to a divisor of your refresh rate, such as 60hz to 30fps if your system cannot sustain 60fps. This can create noticeable and distracting stuttering, hindering smooth gameplay. This is especially noticeable when the performance drops and then has to recover.
The Modern Alternatives
Luckily, with the advent of technologies like AMD FreeSync and NVIDIA G-Sync, VSync is largely becoming obsolete. These adaptive sync technologies dynamically adjust the monitor’s refresh rate to match the GPU’s frame output, eliminating tearing without the associated input lag and stuttering issues of VSync. Additionally, there are faster and smoother VSync alternatives like NVIDIA Fast Sync and AMD Enhanced Sync, which are available on newer GPUs and operate without limiting the frame rate to the monitor’s refresh rate. These technologies provide a much better balance of no tearing and less input lag and can often be enough to stop most screen tearing.
Conclusion
While VSync’s goal of eliminating screen tearing is admirable, its method is ultimately flawed in the context of modern gaming. The input lag and potential for significant frame rate drops and stuttering simply make it unsuitable for competitive gamers and those who prioritize a smooth, responsive experience. If your hardware is good enough to hit refresh rate it may be okay, but with the availability of better solutions like FreeSync, G-Sync, Fast Sync and Enhanced Sync, disabling VSync is usually the best way to maximize your gaming experience.
Frequently Asked Questions (FAQs) about VSync
1. What exactly is VSync?
VSync, short for Vertical Synchronization, is a technology that synchronizes the frame output of your GPU with the refresh rate of your monitor to prevent screen tearing, where parts of different frames appear on screen at the same time.
2. How does VSync cause input lag?
VSync forces the GPU to wait for the monitor’s refresh cycle before sending a new frame. This waiting period introduces a delay between your input and the action on screen, known as input lag.
3. What is screen tearing and why does it happen?
Screen tearing happens when the GPU sends new frames to the monitor before the monitor finishes drawing the current frame, resulting in a visual “tear” on screen. It occurs when the frame rate and refresh rate are not in sync.
4. When is VSync actually useful?
VSync can be useful if your game’s frame rate consistently exceeds your monitor’s refresh rate and screen tearing is occurring. However, there are often better alternatives.
5. Is VSync bad for low-end PCs?
Yes, VSync can be particularly problematic for low-end PCs. If your GPU cannot consistently match the refresh rate, VSync will reduce your frame rate, leading to stuttering and increased input lag.
6. What are G-Sync and FreeSync?
G-Sync (NVIDIA) and FreeSync (AMD) are adaptive sync technologies that dynamically adjust the monitor’s refresh rate to match the GPU’s frame output, eliminating screen tearing without the input lag associated with VSync.
7. Is G-Sync or FreeSync better than VSync?
Yes, G-Sync and FreeSync are far superior to VSync because they eliminate screen tearing without introducing input lag or frame rate reductions.
8. What is Adaptive VSync?
Adaptive VSync is an NVIDIA technology that dynamically turns VSync on and off. It only engages VSync when the frame rate is above the refresh rate, allowing for more fluid performance and less stuttering. However, it can still cause stutter when VSync must re-engage.
9. What is NVIDIA Fast Sync?
NVIDIA Fast Sync is a VSync alternative designed to reduce input lag while still preventing screen tearing, though it is not as precise as technologies like G-Sync and FreeSync. It does this by allowing the GPU to render frames without waiting, and choosing to push the most recent frame for the refresh cycle.
10. What is AMD Enhanced Sync?
AMD Enhanced Sync is an alternative to VSync offered by AMD which aims to prevent tearing without introducing as much input lag. Similar to fast sync it pushes the most recent frame to the monitor on each refresh cycle without the need to wait for vertical sync.
11. Does triple buffering help with VSync?
Triple buffering can improve performance with VSync by using an extra frame buffer to allow the GPU to continue rendering while a frame is being displayed. This can reduce stuttering, but does not eliminate the input lag from VSync.
12. Does VSync limit my FPS to 30?
No, VSync does not inherently limit your frame rate to 30 FPS. If you see 30 FPS with VSync, it usually means your GPU can’t consistently maintain the targeted frame rate (i.e. 60) and VSync is forcing it to a sub-division.
13. Should I use VSync on a 144Hz monitor?
Generally, it is better not to use VSync on a 144Hz monitor unless you are experiencing severe tearing and have no alternative methods for mitigating it. It would be far better to use adaptive sync in conjunction with an fps limiter instead.
14. What is the best VSync option?
Generally, the “Fast” or “Adaptive” VSync options available in the NVIDIA control panel provide more stable frames and less stuttering compared to the regular “On” setting for VSync. However, G-Sync or FreeSync are almost always the best solutions if available.
15. Why do people disable VSync in competitive games?
Competitive gamers typically disable VSync because the input lag it causes can be detrimental to their performance. They often prioritize responsiveness over perfect screen clarity. They often mitigate screen tearing with better hardware and fps limits instead.