Such devices usually come with Y-shaped cable that has two USB connectors to be inserted into a computer.' I have an older USB 2.5' hard drive that includes a power cable that connects to a PS/2 port- I had to use it on older laptops, but not my current laptop. Universal Serial Bus#Power states 'Some devices like high-speed external disk drives may require more than 500 mA of current and therefore cannot be powered from one USB 2.0 port. As to 'full USB power', it depends on the device. I have a USB breakout box I use for this purpose. I would remove all the USB cables and check one of the USB outputs for 5v. Nil Einne ( talk) 15:03, 17 February 2011 (UTC) Reply I agree. 68.102.163.104 ( talk) 16:15, 13 February 2011 (UTC) Reply You have a self powered hub, ones that includes a power adapter to attach to the wall but it still doesn't provide enough power? This is rather odd, I would suggest the hub is potentially defective. Which is why I'm asking my original question. I have one, but apparently it isn't giving bus-powered devices enough power.

one that comes with a seperate power adapter that you plug in to the wall) Nil Einne ( talk) 05:13, 13 February 2011 (UTC) Reply Right. What should I look for when buying a USB hub to make sure each port provides full USB power for each of my devices? - 68.102.163.104 ( talk) 04:30, 13 February 2011 (UTC) Reply If you want to be sure each port of a hub provides enough powr, get a self powered hub (i.e. So what is full USB power? And why is 2X low power always enough power? I hate having to deal with special cables. A user plugs both of them in to get enough power for the device on the other end of the cable. The manuals state this is for USB ports that don't provide 'full USB power'. However, most include a Y-shaped cable with two USB type A plugs on one end.

I have seen portable hard drives, optical drives, and even scanners that get both power and data from a single USB connection.

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