USB 3.0 (U3) Dock: Cable length limited to 1m (3-feet)?


#1

The USB 3.0 (U3) dock seems to only tolerate a 1m cable, as was included in the box. From what I’ve read online, the USB industry recommends that USB 3.0 be limited to 3m or less. I need 2m to be able to plug into the back of my desktop computer under my desk. So far, I have not been able to locate ANY 2m cables, by reputable manufacturers, that work. It’s 1m (3-feet), or nothing…I guess! Shouldn’t this information be made a little more transparent to potential customers?


#2

Hi Wiley,

Yes, unfortunately, USB 3.0 much more sensitive to USB cable quality and length, because of the high rate of transmission (5 GBps vs. USB 2.0 480 Mbps). There are both the USB 3.0 and 2.0 lines running through a USB 3.0 cable – it’s a thicker, less flexible cable.

Because of that, from USB 2.0 to 3.0 the maximum recommended cable length was shortened from 5 meters to 3 meters, and from 5 hops to 3.

Making the difference even more noticeable, many recent USB 2.0 devices and hubs are actually able to do better than the 5 meter recommendation – up to 10 meters or so, while we find USB 3.0 cables are less tolerant in practice for now – USB 3.0 lengths over 1 meter have so far proven unreliable in our experience.

That is why you’re seeing all USB 3.0 devices of all brands shipping with 1 meter or shorter cables right now, except for a few repeaters that push things to 3 meters (which we don’t recommend or sell right now, because we haven’t found them to work consistently enough with all devices, because they’re internally a hub with 3 meter cable built-in. And they definitely run across the U3 SATA dock’s hub limitation).

We think future chipsets and cables will improve things and make at least the 3 meter length reliable, but the status quo is at 1 meter today.

And that does mean if you have a computer that’s on the floor, your USB 3.0 devices have to be there too – which is a pain if it’s a device you have to reach down for (e.g. a hot plug hard device dock like the U3).

The only option to get the longer cable lengths and get the device from the floor to desk is to run the U3 in USB 2.0 mode (with its included USB 2.0 cable, or any longer substitute). That works fine.

Sorry for the bad news. But thanks for pointing this out and asking - hopefully this answer and background will be helpful to others running desktop systems as you are!

Best wishes,
Bernie


#3