MacBook, MacBookPro USB ports are not created equal

by billso on Thursday, 29 May 2008

USB ports are handy, but only when they are fully powered. On some models of the MacBook Pro, it’s the left USB port that is the primary port. If you’ve got an iPod, a headset, a USB-powered hard drive or an external USB hub, plug it in to the left USB port.

The right USB port on the affected MacBook Pro models is hubbed. That means the USB port is sharing the some bus and power source as the keyboard, trackpad, IR receiver, Bluetooth and the iSight video camera. There’s not much power left to run a hungry USB device.

The problem was reported by Andy Ihnatko during the 8 May 2008 MacBreak podcast.

On older MacBooks, the fully-powered USB port is towards the keyboard. The USB port that is nearest to the MagSafe power socket is the hubbed, underpowered port.

I read a Wired article called The MacBook. All USB Ports Are Not Equal and a ZDnet article called (wait for it…) All USB ports aren’t created equal for a few more details, but I checked Apple’s documentation (also at http://snurl.com/appleusb) for the official version. According to Apple, the USB implementation may differ depending on the computer’s model number. It looks like the problem affects older models made in 2006 and 2007. The Wikipedia pages for the MacBook Pro and MacBook can help you determine when your model was built.

The MacBook Air has only one USB port, but it is fully powered.

Image courtesy of wGa HK through a creative commons license.