problems with usb hub

Yes it does.

It cannot draw the power it needs from the computer to power additional devices, including HDDs and charging iDevices.

That's the main reason USB hubs have external power. Otherwise the draw on the single port of the computer would be too great and would burn it out.

 

A single USB port on a computer can put out 500 milliamps I believe. Most Macs will disable the port before damage is caused. That is why you will see low power warnings occasionally. Essentially, use hubs only for printers and other devices with separate power supplies. For the record, an iPad takes 1 Amp (~1,000 milliamps) to charge, an iPhone takes 500 milliamps, and the same for the iPod touch. Couple that with whatever you have plugged into the hub and USB controller on the computer, and you don't have enough juice.

 

In order to get reliable charging, you need a hub with a decent PSU...I use the Satachi which has a labled switchable iPad and iPhone charging port and has a hefty 5AMP PSU.

each bank of ports is switchable and it powers all I've thrown at it..they are not cheap, but you get what you pay for.

 

It is incompatible with the USB 3.0 standard specification (5 V and 0.9 A per port).

0.9 A * 9 ports = 8.1 A
8.1 A + 2.1 A = 10.2 A
5 V * 10.2 A = 51 W


* the 2.1 A value (the 10th "iPad" port) comes from the Satechi FAQ page


That means the Satechi hub needs at least a 51 Watt power supply for USB 3.0 standard compliance. The power supply which comes with the hub delivers only 25 Watt (5 V * 5 A).

See also:
http://www.satechi.net/index.php/computer-accessories/usb-hubs/satechi-10-port-usb-3-hub

HooToo® has a USB 3.0 standard compatible USB 3.0 hub:
http://www.hootoo.com/hootoor-ht-uh010-7-port-usb-3-0-hub-with-2-smart-charging-port.html

 

aha, one more Recommendation:
LOFTEK® Inet SV720 High-Speed USB 3.0 7 Ports Hub + 2 Charging Ports with 5V 2.1A & 5V 1A, 12V 4A Power Adapter and Micro B to USB 3.0 Cable Included
http://www.amazon.com/High-Speed-Ch...qid=1394445695&sr=8-1&keywords=loftek+usb+hub