MBA: Left USB vs Right USB port?

Woochoo · Mar 24, 2015

Hi all, I recently bought a MBA (2014, i5, 4gb) comming from a 2010 Macbook Pro which had both USB's in left side. Well, I've used the old MBP to mix & do live sets (appart from other stuff), and never had problems with the setup (powered soundcard in one USB, powered HUB in the other USB with various midi controllers), despite switching the ports.

The thing is that with the Air, same setup but soundcard on the right USB and HUB on the left, I've haven't had problems (I can't 100% confirm it because I've only used it for one week) till today that I switched both sides.
I've did a lil research and appart from a possible (but not much probable) HUB problem, I've read that the left USB port of the new i5-i7 MBP's and MBA's has more bandwith than the right one because of some internal components attatched to it. So, appart from more tests that I'll do for sure, could anyone confirm me if that's true, so I have to take care of choosing the USB port?

Some stuff about this on this link:
http://www.hardmac.com/news/2010/06/22/macbook-pro-core-ix-usb-ports-are-not-equals

P.S: by "problems" I mean HUGE (various seconds) latency issues on the midi controllers attatched in the USB HUB. Never had those problems before.

Boyd01 · Mar 24, 2015

I have a 2013 MBA and Akai EIE Pro USB audio interface. It seems to work the same on both ports. However, I also have an external USB Apple extended keyboard that has a USB mouse plugged into it. For some reason, it just won't be recognized when I plug it into the right port on the MBA but it works fine connected to the left port.

I thought it might be something in the plug, but the keyboard works fine plugged into a hub connected to the right port, and other peripherals work fine on both the right and left port.

Weird...

Woochoo · Mar 24, 2015

Thnx for the fast reply! Totally, I found it was true... Took a look in Hardware>USB, and one USB is 3.0 Hi-Speed (up to 12Mb/s) and the other one is 3.0 SuperSpeed (up to 5Gb/s). So hugue difference! But how can it be that one has only 12Mb/s?

P.S: a friend with a 15" MBP of 2014 confirms he has the same speeds.

motrek · Mar 24, 2015

Woochoo said:
Thnx for the fast reply! Totally, I found it was true... Took a look in Hardware>USB, and one USB is 3.0 Hi-Speed (up to 12Mb/s) and the other one is 3.0 SuperSpeed (up to 5Gb/s). So hugue difference! But how can it be that one has only 12Mb/s?

P.S: a friend with a 15" MBP of 2014 confirms he has the same speeds.

Depends on what you plug into it. There should be no difference in the ports. If you plug a USB 1 or 2 device into a port it will appear as such in the system profiler.

https://forums.macrumors.com/threads/1406096/

Woochoo · Mar 24, 2015

Mmmm you're right, I switched the audio card and it came up to 480Mbit/s (it's an USB 2.0 card). But it always went to the hi-speed USB 3.0 no matter which port I plugged it at. So that's getting me a lil confused. I think it's time to buy a new USB hub and try again.

magbarn · Mar 24, 2015

I've worn out/broken USB ports before which required expensive logic board repairs so I've come to most often use the USB port that isn't on the same side as the thunderbolt ports. The reason is that the USB port that isn't on the same side as the thunderbolt port is on its own daughter board which is much cheaper to fix/replace. Obviously if you have AppleCare it doesn't matter, but I tend to keep my MacBooks >5 years.

Meister · Mar 24, 2015

Boyd01 said:
I have a 2013 MBA and Akai EIE Pro USB audio interface. It seems to work the same on both ports. However, I also have an external USB Apple extended keyboard that has a USB mouse plugged into it. For some reason, it just won't be recognized when I plug it into the right port on the MBA but it works fine connected to the left port.

I thought it might be something in the plug, but the keyboard works fine plugged into a hub connected to the right port, and other peripherals work fine on both the right and left port.

Weird...

I have the exact same problem.
One usb port works for external mouse/keyboard, the other doesn't.
Everything else works on both.

Anyone else have this problem?

xylitol · Mar 25, 2015

Woochoo said:
Mmmm you're right, I switched the audio card and it came up to 480Mbit/s (it's an USB 2.0 card). But it always went to the hi-speed USB 3.0 no matter which port I plugged it at. So that's getting me a lil confused. I think it's time to buy a new USB hub and try again.

No. Hi-Speed is USB 2 speed and SuperSpeed is USB 3 speed (and the previously mentioned 12 Mb/s is USB 1.1 speed). System Report shows different sections, they do not designate different ports.

FAQ
https://support.apple.com/en-us/HT201163

edit: but I admit that 'USB 3.0 Hi-Speed' section is a bit confusing

xylitol · Mar 25, 2015

Meister said:
I have the exact same problem.
One usb port works for external mouse/keyboard, the other doesn't.
Everything else works on both.

Anyone else have this problem?

my Apple wired kb+mouse combo works on both ports. (2015 MBA 11")

SusanK · Mar 25, 2015

magbarn said:
I've worn out/broken USB ports before which required expensive logic board repairs so I've come to most often use the USB port that isn't on the same side as the thunderbolt ports. The reason is that the USB port that isn't on the same side as the thunderbolt port is on its own daughter board which is much cheaper to fix/replace. Obviously if you have AppleCare it doesn't matter, but I tend to keep my MacBooks >5 years.

Good info. Thanks. I have a mid 2012 MBA with a USB port that will not accept a cable. I wonder what the cost would be to repair? Maybe I'll look into it. It's not on the thunderbolt side.

magbarn · Mar 25, 2015

SusanK said:
Good info. Thanks. I have a mid 2012 MBA with a USB port that will not accept a cable. I wonder what the cost would be to repair? Maybe I'll look into it. It's not on the thunderbolt side.

Below is the 2012 MBA 13 I/O board pics (the MBA 11 is similar, but the part is different), and ifixit sells it for $99

2012 MBA 13 I/O board

If you're proficient or know someone who's worked on laptops before, it should be a relatively easy repair.

EDIT: Don't get it from ifixit, many places like this sell the 2012 MBA 11 I/O board for $35!

Here's a 2012 MBA 13 one for $37 here...

Boyd01 · Mar 25, 2015

Meister said:
I have the exact same problem.
One usb port works for external mouse/keyboard, the other doesn't.

My problem just got stranger. Restarted my MBA for the first time in a couple days and now the Apple extended keyboard doesn't work in EITHER USB port! My USB mouse works in both ports, but not when it's connected to the port on the keyboard.

However, the keyboard works fine if I plug it into my powered USB hub. WTF?

I think it's punishment for posting in this thread.

magbarn · Mar 25, 2015

Boyd01 said:
My problem just got stranger. Restarted my MBA for the first time in a couple days and now the Apple extended keyboard doesn't work in EITHER USB port! My USB mouse works in both ports, but not when it's connected to the port on the keyboard.

However, the keyboard works fine if I plug it into my powered USB hub. WTF? I think it's punishment for posting in this thread.

Sounds like you somehow overloaded the power circuits for the usb ports. It's just supplying just enough juice to power lower load devices, but can't handle higher powered units. Try to see if an iPhone or iPad charges and syncs using the same ports...

Boyd01 · Mar 25, 2015

Thanks, I wondered if it was power related, but I really don't see a pattern here. I tried using only the keyboard with nothing else connected, still didn't work. Other devices, like a flash drive work. My Garmin Montana GPS indicated it was charging while connected.

And now. the keyboard with mouse connected is working again but only on the left port. Very strange.

SusanK · Mar 25, 2015

magbarn said:
Below is the 2012 MBA 13 I/O board pics (the MBA 11 is similar, but the part is different), and ifixit sells it for $99

Image

2012 MBA 13 I/O board

If you're proficient or know someone who's worked on laptops before, it should be a relatively easy repair.

EDIT: Don't get it from ifixit, many places like this sell the 2012 MBA 11 I/O board for $35!

Here's a 2012 MBA 13 one for $37 here...

magbarn, than you so much for the additional information. Extremely helpful. Much appreciated.

magbarn · Mar 26, 2015

SusanK said:
magbarn, than you so much for the additional information. Extremely helpful. Much appreciated.

If you're going to do it, remember the connectors are VERY FRAGILE. It's critical on how you remove them. I've seen too many ham-fisted individuals here ruin perfectly good mac mini logic boards by yanking on connectors or trying to remove them the wrong way.

SusanK · Mar 26, 2015

Thanks. No, I don't have the skills to do this. I would most likely kill my poor MBA. I phoned Apple and MicroCenter today. Now it is a matter of deciding where to take my Mac.

Thanks again for the warning. Much appreciated.

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MBA: Left USB vs Right USB port?

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