What is Input-lag & How to Optimize Your PC

Input lag is the most notorious performance issue gamers will encounter.

Whenever your actions on screen get delayed you are in deep trouble.

It makes you miss crucial shots and the whole experience feels disconnected.

In this ultimate guide, you will learn everything about input-lag

  • What is Input lag
  • Why latency is important
  • How to fix Input lag

One of the best ways to think about this is when you try your favorite retro game that you played on a CRT monitor.

CRT Monitors have close to zero Input-lag meaning we were spoiled in the old days

If you compare it to how it feels when you play the same game on a modern console of your LCD TV you will notice a huge difference.

Games like Megaman and Super Mario are very sensitive to Input-lag.

The slightest delay between inputs and actions on the screen will make the games unplayable.

Modern TV also uses a lot of filters to improve the picture quality which we will learn adds to the latency.

Computer monitors are better even when using “Game Mode” on your television.

What is input-lag?

Input lag is defined by the amount of time between physical action and the visual response on the screen.

More Input-lag will increase the time from when you push the button on your mouse to when your character will fire its gun in the game.

Input-lag is measured in ms (milliseconds) and equals the amount of time between an action and a visual reaction on the screen.

While it’s easy to describe and feel Input-lag it’s often more complicated to understand why and how latency is introduced.

Basically, latency happens in all stages of the processing inside the computer which makes it impossible to eliminate completely.

Why is input-lag bad?


Another way of explaining Input-lag is to describe the floaty feeling you get when using the mouse cursor.

Floaty gameplay makes it harder for the brain to predict future movements which affect our ability to react and adapt.

According to some a difference in 5 ms Input-lag lag is perceivable by humans.


If there is a delay between the physical movement on the Mousepad and the cursor on the screen.

Based on this it’s easy to understand why this behavior is bad for your performance.

During competitive play, your actions need to make an impact instantly.

The goal is to have your skills work 1:1 with your actions in-game because a missed shot can make or break an important match.

Factors impacting input-lag

  • Human reaction time (200-300ms)
  • Input devices
  • Computer processing
  • GPU and graphics
  • Display output and monitor

How to fix input-lag

While it’s easy to explain what Input lag is, how it works in every step is far more complex.

Generally, it’s always a good idea to limit the number of devices, effects, and software running on your system.

Human Reaction time

The importance of sleep

Get enough sleep to stay alert.

Sleep also enhances our ability to predict future actions.

Improves the brain’s speed to process available information.

Keyboard & Mouse

Use 1000 Hz polling rate on your mouse which equals 1 ms added latency, 500 Hz equal 2 ms added to your overall latency.

More devices will add more strain to the USB controller, make sure to disconnect any non-crucial peripherals during important games.

There is some data suggesting that using a high polling rate on multiple devices will interfere with performance.

(If desired you can experiment with lowering the polling rate for the keyboard as it is not as crucial.)


Limit the number of connected devices and make sure the essential drivers are up to date.

Avoid software suits with added functionality such as RGB which will add latency.

Modern drivers are smaller in size which can improve the access time for your system.

The above is one of the main reasons to update your drivers regularly.

Background apps

Limit the number of running applications on the computer, because they will often ping remote servers and may run background tasks on your system stealing resources.

Exit game launchers and other programs when you launch a game, you can always start it again later.

And finally, make sure to disable autostart for non-essential apps when you log in to Windows.


Make sure you always play at your monitor’s native resolution to avoid Input-lag and other side effects.

The monitor is designed to use the native resolution, other settings force the monitor to add an extra layer of processing.

Graphics settings

Performance impact

Higher graphical settings will put an increasing amount of strain on your graphics card.

Avoid the most demanding visual effects in order to keep the GPU utilization below 100%.

Visual enhancements

Anti-Aliasing and other post-processing techniques will increase the visual fidelity at the cost of responsiveness.

A bonus effect is that your own vision will improve, as well as the processing of visual elements inside your brain.

In many cases, lower graphics settings will reduce the amount of clutter and details in the viewport that will distract you from the enemy.

Limit FPS

Limit the FPS output using an application such as Nvidia Control Panel, RTSS or use the in-game FPS limiter.

Different methods come with different pros and cons depending on how your system hardware is balanced.

Limiting the FPS lowers GPU utilization and improves input lag.

(This also has a huge impact on Frame-pacing making it one of the most important settings overall.)

In-game FPS limiter

  • Limits the FPS on a game engine level.
  • Usually results in the lowest impact on input lag.
  • The main downside is the risk of uneven frame timing.

Rivatuner RTSS

  • Limits the FPS using the CPU.
  • Generally adds 1 frame of input lag.
  • Works best if you are not bottlenecked by the CPU.

NVIDIA Control Panel

  • Version 3 of the FPS limiter has improved a lot.
  • Limits the FPS on the (GPU) driver level.
  • Works best if you are not limited by GPU utilization.


V-sync will result in smoother gameplay because every frame is perfectly lined up with the monitor.

The downside is that there is going to be added input latency thanks to how V-sync waits for an even frame output to the monitor.

The key is to find a compromise between input lag and frame-timing to avoid stutter and retain stutter-free gameplay.

Post processing and filters

Limit the number of filters and post-processing techniques in your monitor.

Avoid Anti-Aliasing and other visual filters as they will add to the post-processing and increase Input-lag.

(Bigger problems on TV but still relevant for gaming monitors to some extent.)

Monitor settings

Enable Overdrive to increase pixel response time.

Avoid filters and additional features that add strain and overhead to your monitors.

The input-lag conclusion

If you follow the general steps above you will have a heads start against your opponents.

Combine these concepts with our other more specific guides to optimize your complete setup for increased responsiveness.

And remember high FPS is not all, instead you want a balanced configuration with as low input lag as possible.

By Linus Feldt

I wish I was a professional gamer, but I love marketing.

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