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Is there a maximum length that a USB cable can be?

I want to know if there is an upper limit to its length before it becomes unreliable or useless. If there was also a way to get around this max limit that would be helpful too.

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Amazon link: amazon.com/s/… –  Eduardo Molteni Jun 2 '09 at 1:35
    
It's Albert E. Neuman! I haven't seen that face since I was a kid! (Sorry for a completely useless post - but it brought back memories)! –  Xerxes Jun 2 '09 at 2:10
    
What? Me Worry? –  Eduardo Molteni Jun 2 '09 at 11:36
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4 Answers 4

up vote 9 down vote accepted

From http://en.wikipedia.org/wiki/Universal_Serial_Bus#Maximum_useful_distance -

5 meters for USB2.

If you need to go further you can put a hub in the middle, but many devices have trouble if the distance gets too long.

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Thanks! Forgot to go to the always omnipresent Wikipedia :) –  Eduardo Molteni Jun 2 '09 at 1:36
    
3 meters for USB 3 - lvr.com/usb3faq.htm#ca_maximum –  stukelly Jun 2 '09 at 5:51
    
Thanks for the edit, Joel. Much better. –  Matt Simmons Jun 7 '09 at 20:23
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You can get an USB to ethernet extender, that can extend your connection a much further distance. For example:

http://www.iogear.com/product/GUCE51/

We are using this product to extend a USB connection about 25 feet.

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There are also "active" extension cables that are a 5 meter cable with a 1 port hub built into the far end.

I've heard as many as 5 can be chained together to go farther. Latency starts to become an issue, and many USB drivers do not handle the distance well. It works well enough for remote keyboards and mice.

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Last time I tried to plug a hub into a hub, it didn't work. –  niXar Jun 2 '09 at 11:38
    
@niXar: hub into hub should be OK, but at least one of them will need to be powered. –  Richard Jun 2 '09 at 13:09
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Had USB running at 6m & 8m, so it will go a bit above the spec, but that was "only" a keyboard/mouse. Used this with lengthy VGA cables on an expo stand.

Not tried any of the "USB-over-cat5" kit yet.. but I kinda fancy it - would stop the stand contractor putting the cables in backwards at least!

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and how did you get cables this long? Only 5mts cables are on sale on Amazon –  Eduardo Molteni Jun 3 '09 at 12:19
    
This sounds like it should be the punchline for a bad joke... but "join 2 together"? :) Just used 2 consecutive extenders (plus the length of keyboard cable it may have been up to 9m) –  Tom Newton Jun 4 '09 at 7:13
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