DP 1.4 KVM Dropping Display Signal While Gaming

Level1_Amber · December 21, 2023, 4:47pm

All copper cabling will degrade your signal over time. Some are better than others because the copper is thicker.

To combat this, as a general rule of thumb I think Wendell recommends the total length to be no more than 10ft.
I would encourage you to read that section of our FAQ for a better explanation:

[Official] L1Techs KVM FAQ -- Ultimate Guide & Help!

Importance of Length

Degrading Signal

The more cable length and connections you have, the more the signal will degrade. You will lose a bit of signal through the KVM; there is no repeater in it. This is necessary because the KVM aspires to be a big dumb switch so it would not interfere with Nvidia G-Sync/AMD Freesync. This way you have fewer problems trying to use whatever hot new thing that hasn’t come out yet. Also, this helps us stick closer to the DP 1.4 raw specification without having to get creative.

Shorter Is Better!!

So keeping the total run length from GPU to Monitor to about 10 feet (~3 meters) or less is important, especially for higher res/refresh. Certain combinations of equipment may require a 3+3 foot cable combination, for example. That’s a total length of about 6 feet, or roughly equivalent to what you’d have with a single cable.

How The KVM Sees Cables

With this setup, your GPU sees one long signal corridor from the DP connector on the GPU all the way to the display. So a 6+3 foot cable is like as if you have about a 10-foot cable. Two 10-foot copper cables are not going to work.

A way to sort of circumvent this is with fiber optic cabling. That can be a little expensive, but it would get rid of the signal degradation issue. You’ll be able to keep your setup where it is instead of buying shorter cables and rearranging:

If anything, buy 1x of these fiber optic cables to replace your very long 10 foot cord. That might be enough to solve your issue, since the drop is occurring intermittently when you’re using the PC connected with that long cable.