Maximum Number Of USB Capability

HI Guys,

I was just wondering I have obviously got my 4USB ports on my Mac and I have a 4 USB Hub external adapter! I only have 1 hub left out of those 8!
I just spoke to my dad and he said running 12 might be a bit to much to ask from the computer! What do you guys think is the maximum USB ports I could run of my 21.5" iMac without causing damage or slowing it down?

I look forward to your fast reply!

Cheers,

Matt

It all depends on what you have plugged in.

If you have lots of energy-hungry products (printers, scanners etc) those will force the port to stop working since they are drawing so much power. If they are just mice / external hard drives etc it should be fine.

I would recommend an AC powered hub tho just to be safe.

Would one of those be expensive? (AC powered usb hub) All in this is what I have plugged in AT THE MOMENT! LOL!

iPhone sync cable (from mac)
Extra Hub
USB Extender (Running from hub)
2x External HDD's (1 from mac the other from the hub)
Camera Sync cable (sometimes) - (USB extender cable)
Printer (from hub)
that is just about it I have 2 more apple sync cables that I need to use to sync all of my gadgets at once!

Yes with all that a mains powered hub.

Would this be any good?
Premium 7 Port Ports USB 2.0 Powered Hub AC Adapter xp on eBay (end time 07-Jan-11 17:07:22 GMT)

Targus Desktop 7-Port USB 2.0 hub with AC Adapter - Hub - 7 ports - Hi-Speed USB: Amazon.co.uk: Computers & Accessories

That one looks very good! Another amateur question when I plug my iPhone into my non powered USB Hub it says charging is not supported with the one I just linked to would it charge my iPhone etc from that?

The Targus is a good brand. Can't answer your iPhone question as don't have one. If an iPhone charges via USB then it should charge from the Targus.

Another √ vote for the Targus. It has two 1000 mA ports for high-demand devices, eg, charging a phone. I don't use the audio pass-through on my Targus, as it generates a buzz/hum, audible through the external amp/spkr system.

Cool! I will take my old crappy bush hub back and get the targus

Here's an article regarding how much power a USB port on a computer "puts out":

What Is the Power Output for a USB Port? | eHow.com

500mA seems to be a common value. So you would have to sum up the total milliamps drawn for all USB devices plugged into a computers single USB port...to know if you're getting close to that ports power output limit.

- Nick

Thanks !