Maximum Cable Lengths

- Posted in: Tech Talk
Maximum Cable Lengths
The DocKtor often gets asks, "What is the maximum USB cable length?" or "What is the maximum length of HDMI, VGA, & DVI cables?" Targus has validated using the in-box 1m cable (ACC987USX) with the Targus USB3.0 extension cable (ACC985USZ) to 13 feet between the PC and the dock. All other interfaces (ports, connections) conform to their respective specifications. Calculating the theoretical maximums using timing diagrams would be misleading because connector and cable quality vary widely. The DocKtor realizes this is not much of an answer, but that is because the specifications do not specify a maximum length:
  1. USB Cabling

  2. HDMI Cable

  3. DVI-D Cable length

  4. VGA (and DVI-A portion of DVI-I) Cable quality

There are many third party solutions for extending these interfaces. The DocKtor is aware of VGA, DVI, and HDMI cables running well over 20 feet and he has even used USB active extension cables to about 20 feet. Myadvice would be to understand the application(s) and buy appropriate quality cables. The DocKtor can offer advice and even test cables at times, but I would have to know the specific devices to be used also. Feel free to document your application specifics in reply to this blog and we will take a look. Bonus: Ethernet CAT6 and CAT5 are 100m.