USB hub

[Bob Ober]

     I have two USB-3 hubs, a 7-port and a 10-port, that seem to be 
working fine.
     If you are looking for a multiport hub, I think the power supply 
output and port current ratings are the most important criteria.
    According to System Information, one hub is rated at 900 mA (4.5 
watts)  per port, and the other at 500 mA (2.5 watts).   Which means 
that demand on a 7 port hub could be as high as 30 watts.  When 
researching for mine, I found that some 7 port hub's power supplies 
rated as low as 12 watts max which is probably enough for most people 
most of the time, but leaves little room for a safety margin.
     It's hard to tell how much overall power your hub will actually 
need.  Rarely if ever, will all ports be running at max, but too little 
available power can be fatal.  As of right now, most connections to my 
hubs are drawing less than 100 mA, or a little under a watt each.  If 
you will be plugging in any additional unpowered equipment like portable 
hard drives or cell phones, they will draw every watt available from the 
port, and you can very quickly exceed the power supply's capacity.  
IPhones and iPads will draw on the order of 10 to 15 watts each, if the 
power is available.  By itself, enough to overload some hubs.
      Both of my hub's power supplies are rated at 20 watts and I never 
plug my phone or iPad into them..  I would have paid for even more 
capacity if the prices didn't start skyrocketing above that rating.

     My W800 is currently plugged into a powered internet converter so I 
don't know what it's drawing, but running the System Information will 
give you the current draw on each USB device.

Bob

On 6/13/15 11:21 PM, Chuck wrote:
> I have some of my interfaces plugged into a USB hub and then plugged into the back of a Mac Mini. I am thinking that maybe there's not enough power in this hub. It's an old hub and I was thinking about upgrading.
>
> I am almost sure that my W800 USB is not getting enough power.
>
> On Amazon I was looking at the Anker seven port USB hub. I have several Anker products and I'm very happy with them so far. They have an 18 month warranty and I had a device go bad and they sent me a new one, no questions asked. In this day and age you can't beat that kind of service.
>
> Any thoughts on this issue?
>
> Chuck
>
> Sent from my iPad and butchered by Siri
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