USB extension

[Digital Viper-X-]

Looking at getting one for my htpc to use my kb and mouse with, how long are they generally good for? a 25foot "active" cable connected to a hub at the kb/mouse end, would that work?

 

[timta2]

You should be good. I used to use a USB 1.0 printer on a 25 foot non-active cable and it worked fine. I'm sure with those low bandwidth devices you will be ok.

http://en.wikipedia.org/wiki/USB

The USB 1.1 Standard specifies that a standard cable can have a maximum length of 3 meters with devices operating at Low Speed (1.5 Mbit/s), and a maximum length of 5 meters with devices operating at Full Speed 12 Mbit/s.[citation needed]
USB 2.0 provides for a maximum cable length of 5 meters for devices running at Hi Speed (480 Mbit/s). The primary reason for this limit is the maximum allowed round-trip delay of about 1.5 μs. If USB host commands are unanswered by the USB device within the allowed time, the host considers the command lost. When adding USB device response time, delays from the maximum number of hubs added to the delays from connecting cables, the maximum acceptable delay per cable amounts to 26 ns.[51] The USB 2.0 specification requires that cable delay be less than 5.2 ns per meter (192 000 km/s, which is close to the maximum achievable transmission speed for standard copper wire).
The USB 3.0 standard does not directly specify a maximum cable length, requiring only that all cables meet an electrical specification: for copper cabling with AWG 26 wires the maximum practical length is 3 meters (9.8 ft).[52]

 

[evilsofa]

Monoprice doesn't sell cables that don't work, so I often look to see what they're selling to get an idea of what lengths work in practice.

Their longest USB 2.0 extension cable is 25 meters (82 feet). Their longest USB 3.0 extension cable is 6 feet.

http://www.monoprice.com/Category?c_id=102&cp_id=10303