What is Input Lag?

Diagram of Input Lag

There are multiple variables that can affect the time it takes for the input action to have an affect onscreen. Some you can control, others not so much.

We’re going to go in to some detail on each type and explain how we can control them if we can.

The Controller

Most modern game controllers are fine, but every now and again are susceptible to input delay. This is commonly due to distance from the console, or interference.

Switch Joycons have a relatively short range, and the PS4 controller has a medium range. The Xbox one controller communicates over a proprietary wireless technology, but the third revision supports Bluetooth for PC connectivity without a Xbox receiver.

Any experienced delay can often be gotten around by going wired, removing interference, or moving closer to the console.

The Console

This is the crux of LagDB.com – It’s the internals of how the game is programmed. The rendering engines of the game have a large amount of control over how they output the image. They can be hard programmed to output at certain resolutions, certain frame-rates, and have x amount of frame buffer. It is often the frame buffer that causes input delay. The reason for this is developers priotising image quality over performance. A small amount of delay allows the image to be cleaned up or completed perfectly before outputting. The thing is, this isn’t a on or off option. It’s a configurable series or grey areas that with a bit of attention and care can be minamised. You could even give the end user the choice!

The most common cause is V-Sync. Basicly V-Sync is the solution to screen tearing. Screen tearing happens when the monitor requests a new image, but the hardware has not yet finished drawing the image. You end up seeing part of one frame, and part of another with a ‘tear’ down the middle. The solution for this was V-Sync. It waits for a frame to be 100% finished before sending it out. This adds a small amount of delay and is especially noticeable at lower framerates. It also can result in stuttering if the time it takes to render frames is inconsistent. The solution to this is Buffering. Similar to how Youtube will spend some time buffering (downloading frames and audio before displaying them to you) games often buffer up to 3 frames, known as tripple buffering. This means that the output of your instruction gets put in line behind 3 frames waiting to be sent to the display. I feel that Overwatch on PS4 this is most noticeable. The gameplay is incredibly smooth, but the input lag is insane.

In my perfect world, developers would offer 3 options, VSync on (tripple buffer), VSync on (single buffer) and VSync Off.

The above issues is what InputLag DB considers to be a solvable problem, but only by the developers.

(Optional) Video Amp

Some may have a video amp either to simply pass through your multiple HDMI inputs in to a single HDMI output – It may additionally support some kind of video scaling or processing, which may or may not add a delay. You will be looking for options such as ‘STRAIGHT’ so that no processing is done to the image.

Display

Last but not least is the display. Whether a TV or a PC Monitor – Both can add delay and both have options to combat it. Sometimes you just have a panel with a high response rate. Really only bad for competitive gamers. What can really be noticed however is processing of the image. Often TVs and displays will come with something called ‘Game Mode’ what ‘Game Mode’ actually does is usually 2 things. The first is disabling any kind of post processing that would add an input delay. Often things like refreshrate or resolution up-sampling. These things are nice for image quality, but at the end of the day the ability to aim that headshot or time that jump accurately is probably more important. The other thing they can do is simply adjust brightness and contrast settings for image clarity however that is not very relevant here.

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