Does cable length increase monitor input lag?

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BlazeGaming
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Does cable length increase monitor input lag?

Post by BlazeGaming » 30 Jun 2020, 13:53

Hi. I just bought 2 DP version 1.4 8k certified passive cables for 2 of my monitors. One has 3 meters and will be using it on an X34p 3440x1440p @ 120hz and a 5 meter one to use on my Acer XB272 1080p 240hz monitor. I don't want to use the short cables that the monitors came with because I've revamped my setup and my unit is pretty far away and also need the length for proper cable management. Question is: Does the extra length affect my monitors input lag or bring any other disadvantages?

davidoo
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Re: Does cable length increase monitor input lag?

Post by davidoo » 30 Jun 2020, 14:03

No.
You're fine.

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RealNC
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Re: Does cable length increase monitor input lag?

Post by RealNC » 30 Jun 2020, 18:41

Well, you can do the math if you want. Inside a cable, the signal travels at about 70% the speed of light. That's 209.854.721 m/s. So to increase lag by 1 millisecond, your cable would have to be 210 kilometers long (130 miles) :mrgreen:
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Chief Blur Buster
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Re: Does cable length increase monitor input lag?

Post by Chief Blur Buster » 30 Jun 2020, 19:06

What RealNC said.

Cable length is meaningless unless you've got a repeater/switch/amplifier. Those can add lag. But a 3 foot versus 5 foot DisplayPort? The lag difference is only nanoseconds. Even a 1-degree temperature cooler room temperature will speed up your computer (less thermal throttling) far more than that -- hell, even just blowing air on your computer with your lips.

Don't worry about cable lengths.
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1000WATT
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Re: Does cable length increase monitor input lag?

Post by 1000WATT » 30 Jun 2020, 19:46

Chief, you play a dangerous game. This can be another point in the guide for tuning, optimization, and reducing delays. Timer sellers appreciate such material. In the next video, FR33THY will blowing air lips for 1.5 hours into the system unit with interruptions to tell that it helps and is very important. And you can’t argue with them, as it’s true.
I often do not clearly state my thoughts. google translate is far from perfect. And in addition to the translator, I myself am mistaken. Do not take me seriously.

BlazeGaming
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Re: Does cable length increase monitor input lag?

Post by BlazeGaming » 30 Jun 2020, 21:04

Thanks Cheif and all others for the detailed and fast answers, best forum and website when it comes to monitor knowledge, always helpful people around here.

BlazeGaming
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Re: Does cable length increase monitor input lag?

Post by BlazeGaming » 01 Jul 2020, 15:30

Back with more questions, didn't want to make a new post. Apparently my mouse and keyboard cables aren't long enough either, what are my options to avoid input lag on both? Cable extensions? Is it safe to use a usb hub with a longer cable for both?

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Chief Blur Buster
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Re: Does cable length increase monitor input lag?

Post by Chief Blur Buster » 01 Jul 2020, 15:41

1000WATT wrote:
30 Jun 2020, 19:46
Chief, you play a dangerous game. This can be another point in the guide for tuning, optimization, and reducing delays. Timer sellers appreciate such material. In the next video, FR33THY will blowing air lips for 1.5 hours into the system unit with interruptions to tell that it helps and is very important. And you can’t argue with them, as it’s true.
Ha.

Unfortunately, lots of placebo effects with these kinds of tips.

Thankfully the human-blow tip is a self-error-correcting and self-shaming manoeuvre, because commentators will say “why is this airhead blowing at his computer? Why not add another computer fan? It’ll perform cooling better”. Homer Simpson zero brainer “doh” moment. Spinning fans and heatsinks are known to prevent thermal throttling & improve performance. As a well known science, so there’s that...

BTW, I now have a copper HDMI cable and optical-fiber HDMI, I will be testing lag differences of that to see if it’s meaningdul (there’s a signal converter of sorts). Probably not a measurable difference, but worth me doublechecking media-conversion latencies.
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Re: Does cable length increase monitor input lag?

Post by Chief Blur Buster » 01 Jul 2020, 15:50

BlazeGaming wrote:
01 Jul 2020, 15:30
Back with more questions, didn't want to make a new post. Apparently my mouse and keyboard cables aren't long enough either, what are my options to avoid input lag on both? Cable extensions? Is it safe to use a usb hub with a longer cable for both?
Hubs add lag.

Longer cables without a hub is better. Use a passive extension cable, you can go up to about 5 meters.
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       • List of FreeSync Monitors
       • List of Ultrawide Monitors

BlazeGaming
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Re: Does cable length increase monitor input lag?

Post by BlazeGaming » 01 Jul 2020, 16:11

Chief Blur Buster wrote:
01 Jul 2020, 15:50

Hubs add lag.

Longer cables without a hub is better. Use a passive extension cable, you can go up to about 5 meters.
I just got done watching this https://www.youtube.com/watch?v=nbu3ySrRNVc Not sure if you saw it or approve his methods of testing.

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