HDMI interface is one of the most popular, if not THE most popular, display interfaces used. This is because this interface is capable of carrying audio signals along with video signals, while maintaining data security.
But does all of this come at a cost of lag? Do the HDMI cables that connect the source devices to display devices have an inherent problem with input lags?
The short and simple answer to the age old question “does HDMI cable cause lag” is a big no. This is a myth that has been busted time and again. HDMI cables do not cause any lags. The input lags you experience are mostly caused by the TV, monitor or the projector itself.
A lot of people unfortunately still believe HDMI cables cause lag when connecting to a TV or a monitor. Let’s find out if that is true.
What is Input Lag?
There are many different kind of lags.
Some lags, for instance, are caused by lower frame rate. For instance, when playing a game, if your graphics card cannot keep up with the quality and the resolution of the graphics you have set, then that may cause frame rate to drop. Anything below 30 frames per second would lead to lags.
Other lags are caused due to tearing. This occurs when there is a misalignment of Refresh Rate of the TV/monitor with the frame rate of the source device i.e PC, gaming console. This issue is generally resolved through enabling V-Sync or through technologies like AMD’s Freesync.
There are also certain lags that caused by bad drivers. This is generally seen on PCs. Bad drivers can lead to issues with poor optimization leading to lags.
INPUT LAG, however, is a completely different kind of lag. Input lag is also known as input delay or Display Lag.
It is basically the latency or the span of time it takes for the audio/video signal to travel from the source device to your TV or monitor’s display.
There are many stages a video/audio signal has to go through from the source device to your TV’s display. All of these stages take time.
The processing of the video/audio signal AT THE HDMI INPUT side (on the TV) as well as the Pixel Response Time of your TV – or the time it takes the pixels on your TV to turn from OFF to ON state – can be summarized as the input lag.
So Does HDMI Cable Cause Lag?
Let’s get straight to the point. HDMI cable ITSELF does not cause any lags whatsoever if it is visibly and physically in good condition – which most of the time HDMI cables are.
There is nothing inherently wrong with the HDMI cable, the connector or the port itself in majority of the cases that would lead to a lag. Unless you have a physically damaged HDMI connector on the cable or a damaged HDMI port, you cannot put the blame of an input lag on the HDMI cable itself.
But this does not mean you won’t feel any delays while using HDMI cables with your TV. The input lag that you see has nothing to do with the HDMI interface at all. Instead, it has to do with processing that has to be done by chips on the TV.
The better the microchips, the lower will be the input lag.
All digital multimedia interfaces have input lags again due to all the digital processing that has to take place within the TV.
However, in majority of the instance, the input lags are unnoticeable. If you are experiencing visible input lags then it’s most likely that the device you’re connected to that is causing input delays.
In other words, it is the processing capability of TV that should be blamed for the input lag.
Also Read: Does it Matter Which HDMI Port I Use?
Case Study By Shmup Junkie
Shmup Junkie is an expert at making audio/video systems.
He tested comprehensively whether an HDMI cable can actually cause lags or not. TL;DR. he concluded the belief that HDMI cables cause lags is just a myth and not based on any firm ground.
He tested this in multiple ways using the video input lag testing device.
He first tested it directly by connecting the cable to from the test to the TV and got an input lag of 14ms (at the center of the display).
He then tested the same by routing the HDMI cable through an HDMI Matrix. Basically, the HDMI Matrix can be substituted for a PC, gaming console or a set top box.
This setup required two HDMI cables. One going from the tester to the HDMI matrix and the other going from the HDMI matrix to the TV. And as expected, the result was still the same 14ms of delay.
He then tested again with a 100ft HDMI cable and a complex system not just with a single HDMI matrix, but two HDMI matrix which were connected via CAT5 ethernet cable and lo and behold the result was still the same 14ms of delay.
It should be noted that while the HDMI cable does not cause any lags, there is a still a 14ms of lag that is generated due the delays in video processing inside the TV itself. This lag has nothing to do with the HDMI cable or the HDMI interface and everything to do with the image processing technology and chips within the TV.
Here is the complete video:
What Might Cause Lag While Using HDMI?
Let see the first things that come into your mind to blame for the input lag.
The Device You’re Viewing the Content On?
Yes, this is quite likely.
As mentioned earlier, the processing capability of the TV or the projector could be a cause of the input delay.
You might see a bit of delay on your TV because they are designed with a “buffer” period that manages the signal delay between different devices.
So it’s actually your TV that is causing the lag, not the HDMI itself. Your TV has varying degrees of input lag depending on the make and model. This can range anywhere between 10 milliseconds to 100+ milliseconds.
The higher the resolution of the TV, the higher is the input lag generally due to the fact the higher resolution requires a lot more processing.
An Old HDMI Connector / Port?
This is highly unlikely.
If your HDMI connector / port has not signs of damage, then it is highly unlikely to be cause of lags.
When in doubt, try using a different highly quality HDMI connector
I must mention here that one possible cause of your HDMI connection being sluggish may not be related to input lag at all.
If you are connecting input and output devices with different HDMI versions, then that could lead to issues which you may confuse with input lag instead.
Read Further on this Topic Here: How to Check the Version of Your HDMI Ports?
Also Read: How to Check HDMI Cable Version?
An Old Game Console?
An old gaming gaming console or a gaming PC has nothing to do with input lag.
You may be confusing input lag with frame rate lags caused by obsolete hardware.
Length of the HDMI Cable?
This is a popular misconception.
Cable length does not have a noticeable impact on the input delay whatsoever. The study detailed in this article clearly shows that the length of your HDMI cable has negligible effects on the input lag.
To Conclude: What Causes Input Lag?
So to conclude. It is your TV, monitor or the projector that is responsible for the input lag (mostly TVs).
Monitors have a superior performance and generally have barely noticeable input lags.
TVs are the obvious culprits for any form of input lag particularly if it is noticeable. The only solution here is to make the right choice when buying your next TV.
Dealing With Input Lag
So you are experiencing input lag on your TV, what are the quickest options you have to reducing the annoying input lags?
Enable Game Mode on TVs
A lot of TVs come with a ‘game mode.’
Enabling this mode reduces the post-processing done by the TV.
So essentially, it allows the TV to stop non-essential processing so that that it can pump out the frames as quickly as it can.
This mode is meant to mirror the low-latency gaming monitors that have input delays as low as 3 milliseconds!
Free Up the Processing on the TV Further
Think of a TV as a computer. It has a limited processing capability. The more processes you turn off, the more room it will have to dedicate its resources to pushing out frames as quickly as possible.
Therefore, non-essential settings such as noise reduction, and other enhancement settings should be turned off.
Using a Low Latency Monitor
If you are a competitive gamer and if each and every ms of lag counts for your, then it would be wise to switch to a monitor.
Average monitors are superior in performance and have a much lower input lag. It is not uncommon to find average monitors with are mere 2-3ms of input lag.
Whereas average TVs have a response time a 100ms easily (if not in game mode). Here are the Tests.
Also Read: Does HDMI Drain Battery?
So does HDMI cause input lag? No, it does not. HDMI does not cause delays or input lag.
It is usually the display device, such as the TV that is main culprit for any form of input delay.
If you have tester, you can test this by yourself. Try playing a game on a monitor and on a TV using the same HDMI cable. You will notice the TV has a greater lag as compared to the monitor.
If you have further information to share, please let us all know in the comments below: