USB 3.0 Hub for my iMac

Question

USB 3.0 Hub for my iMac

Good Day!

Just obtained a Belkin 4 port Hub model : F4U073 purchased through MacStore online.

http://store.apple.com/us/product/HD988ZM/A/belkin-4-port-usb-30-powered-hub?fno de=58

My main purpose was to connect my SuperDrive to it but it doesn't connect.

A message comes up on my iMac monitor indicating that the SuperDrive USB Apple needs to be connected to a Mac's USB port.

3 Questions :

Why is this? Any idea?
Is it worth the purchase or investment if I connect other USB cables to the USB Hub and attach the SuperDrive to the iMac's USB port?
Do I need to use the Power Supply for it to work on my iMac? (It seems to work without it.)
Do I need to use the Power Supply for it to work on a MacBook? (Haven't tried it yet)

Cheers for the New Year!

It will be going down to -20° C or -6° F tonight.

Keeping warm...

iMac, OS X Mavericks (10.9), late 2012

Posted on Dec 31, 2013 11:37 AM

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Answer 1

rkaufmann87

Level 10

148,624 points

Dec 31, 2013 11:40 AM in response to francoontarienOttawa

iMacs USB busses do not have enough power to operate non powered USB hubs. I'd recommend either powering the USB hub you have or replacing it with a powered USB hub.

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Answer 2

Dec 31, 2013 12:04 PM in response to rkaufmann87

Thanks for your response.

My USB hub has a power supply.

Is this similar to what you mean by a Powered USB hub?

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Answer 3

rkaufmann87

Level 10

148,624 points

Dec 31, 2013 12:14 PM in response to francoontarienOttawa

Yes.

On a external Superdrive I'd just plug it into one of the internal USB ports the iMac has. Try connecting other peripherals such as external HD to the hub and if it doesn't work then it might have problems. You can do some SMC resets first before returning it but if after the resets it still will not work then it appears you got a bad one.

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Answer 4

Dec 31, 2013 12:34 PM in response to rkaufmann87

Thanks for your reply.

Actually, I have my external HD connected by the Firewire adapter to the Thunderbolt port.

2 questions :

What are "SMC" resets?
What does the power supply actually do for the USB hub if some connections don't seem to need a power supply for them to operate on it?

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Answer 5

rkaufmann87

Level 10

148,624 points

Dec 31, 2013 12:48 PM in response to francoontarienOttawa

To learn what a SMC reset is please read Apple's Intel-based Macs: Resetting the System Management Controller (SMC) located at: http://support.apple.com/kb/ht3964.

You need a powered USB hub because iMacs USB ports do not supply enough power to run unpowered hubs. I explained that in my first post. You might get lucky and get 1-2 perihpals to work without power however if you add additional devices they won't be seen because you are overloading the power abilities of the iMacs USB port. Look at the system specifications for your machine and you will find where Apple advises how much power their USB ports provide.

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Answer 6

Linc Davis

Level 10

209,739 points

Dec 31, 2013 1:09 PM in response to francoontarienOttawa

Why is this?

It's because the Apple Superdrive is bus-powered and draws more power than a standard USB port can supply. Macs that don't have a built-in optical drive are designed to work with it. Third-party hubs are not.

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Answer 7

Dr.Mac.

Level 3

650 points

Dec 31, 2013 1:28 PM in response to francoontarienOttawa

SMC Reset:

Shut down the iMac
Unplug the iMac's power cord.
Wait fifteen seconds.
Attach the iMac's power cord.
Wait five seconds, then press the power button to turn on the iMac.

The SuperDrive device must be plugged directly into your iMac.
A SuperDrive device connected to a hub will not have access to extra power above the standard USB specification of the port the device is connecting to (500 mA for USB 2, and 900 mA for USB 3).
The USB port providing extra power is determined by the SuperDrive device that requires power beyond 500 mA for USB 2, or 900 mA for USB 3. The remaining ports will continue to offer their normal maximum output. Some Apple Macsmay offer the ability to operate more than one USB port at 1100 mA at 5 V. On those computers, the second port is enabled when an appropriate device is connected.

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