Need DisplayLink Advice - 35Ft. DisplayPort Cable

[Smartian]

Hello,

I work customer support for a Display manufacturer and have a customer experiencing issues using my Display product and the Dell 3100 Dock with the USB to DisplayPort adapter built in.

We recommend using no more than a 7m(23ft.) cable to our customers, however they are using a 10.6m(35ft). cable between the devices and are seeing artifacts when playing video.

I highly suspect they are using a cable that is simply too long, but rather then just dropping the signal I think we are in the grey area where we see enough signal degradation to cause video issues, but not enough to cause the video to actually drop.

I I have not been able to find any literature that calls out maximum cable lengths, but I'm looking to justify to the customer why they need a proper powered extender here, and if you cab share any advice that would be helpful.

Thanks!