MacBook USB port, under scrutiny. Photo: Kevin Hiscott.

Is your MacBook Pro a rightie?

Something’s going on with the one or two left-hand USB ports on all MacBook Pros. I’ve heard some issues with hard disks, and now some problems with audio. (Controllers are evidently just fine.) The solution: use the right-hand USB port for audio instead.

Updated: Reader Adam suggests that this is probably due to a difference in power delivered to the respective ports. USB audio requires more power, and so odds are you’re under-delivering on the left-hand ports. I’m inclined to think that this is exactly what’s going on – unless someone knows something else. (Easy way to test: try plugging in the power adapter. Note that this can be an issue with FireWire, too.)

In fact, even if for some reason M-Audio has found another reason behind this, Andy Ihnatko noted the issue with different USB ports and power variation way back in 2008. It affects non-Pro MacBooks, and I expect likely many PCs, too.

The MacBook. All USB Ports Are Not Equal [Wired Gadget Lab]

M-Audio (now Avid) has gone as far as to tell its customers officially to avoid the use of that port for audio entirely. Native Instruments forum users have evidently had similar discussions. Via matt_bot on Twitter:

The use of USB Audio Devices on the Left-Hand USB Port Is Not Recommended.  This applies to ALL MacBook Pro Models (Core Duo and Core 2 Duo).

•    The 15" MacBook Pro models have 1 USB port on the left side, and one USB port on the right side.
•    The 17" MacBook Pro models have 2 USB ports on the left side, and one USB port on the right side.

Due to the current USB configuration of the 15" MacBook Pro under OS X, use of USB audio devices is supported on the right-hand USB port only.  Use of such devices on the left-hand USB port(s) is not advised because it may cause audio interrupts and/or dropped samples.  However, the use of an iLok on the left-hand port has been qualified and is fully supported.

Due to the current USB configuration of the 17" MacBook Pro under OS X, use of USB audio devices is only supported on the right-hand USB port, and the left-hand USB port farthest from the screen.  Use of such devices on the left-hand USB port closest to the screen is not advised because it may cause audio interrupts and/or dropped samples.  However, the use of an iLok on the left-hand port has been qualified and is fully supported.

These USB port recommendations are specific to USB Audio devices only (such as the FastTrack USB or Audiophile USB).  USB Keyboard and Control Surface products do not have a recommended USB port at this time.

MacBook Pro recommended USB port(s)

That’s got to be a tough technical advisory to issue, like having to tell your users they should turn around in their chair three times counter-clockwise and shout “Mimmymabby” before recording. But I’ve heard indications that devices other than M-Audio’s are seeing symptoms, so I’m inclined to believe there may be something to this.

Now, before you use this to assume this means FireWire is better than USB or PCs are better than Macs or veganism is better for your love life or the end times are upon us, the whole point is what’s causing the issue and why. (Correction: I’m satisfied enough with Adam – and Andy Ihnatko’s – explanation above that I think there’s not much mystery here! So quit with conspiracy folks and trashing vendors you don’t like, folks. Technology doesn’t need superstition; it needs users hungry to know what’s actually going on.)

Of course, that raises a question: why are some USB ports not entirely up to spec on power? My hope would be that USB is USB and you don’t have power variations between ports, but then, I live in a fantasy world of naive hope. (Can anyone comment on PC laptops and power on different ports? I imagine some would have exactly the same issue.)

One theory for the power discrepancy: John von Seggern claims via Twitter that the issue could be the iSight video camera, which does indeed use the USB video bus. (I would think it shouldn’t draw power when switched off, but perhaps that has caused some other change in the configuration.)

Further, we have reports that not only the iSight, but also Bluetooth and other power-consuming peripherals are on the same bus, as well. (That means turning off Bluetooth might be a good idea if you don’t already.) And we have at least one PC with the same issue. This will definitely be something to research with computers, as it’d be pretty desirable to get machines that, erm, don’t do this to their USB ports.

And someone’s having the opposite port work or not work? Now I’m really confused. (I guess we could simplify all of this to say if you’re having problems with USB audio, try either connecting your AC adapter or switching USB ports.)

Amidst all of the USB audio hating, I have to say, it is possible to get good performance out of USB audio interfaces. On the other hand, removing FireWire from MacBooks seems again like a poor choice.

  • kipplekeeper

    it should be noted that microsoft and avid are very close, and both use each other to push their own brands. while there very well could be some truth to these statements, the report might be sightly sensationalized to create negative PR for macs.

    personally I've never run into an issue using the left USB port, however a long time ago I remember hearing that the left port didn't put out as much power as the right on some macbook pros.

  • Is anyone with any sense still buying M-Audio products? Headline should read, "Avoid M-Audio, both left and right"

  • This is because the power-over-USB isn't powerful enough on the left hand ports. This goes for Macbooks too, where for many USB-powered devices you have to use the port farthest from the screen.

  • My Axiom 25 is the best controller I've owned, and the piece of hardware that causes me the fewest headaches. Even on my left USB port. So, what's the problem with M-Audio?

  • @kipplekeeper:
    Come on. Give me a break. Avid has one concern, and that's selling their products. Microsoft has an interest in *pushing Avid*, because it gives their Windows platform an alternative to the Mac-only Final Cut Studio and Logic Studio. But if you're Avid, you have exactly zero interest in one OS versus another. This is a technical note for people who have already purchased one of these machines. I don't see any conspiracy theories here.

    @actuel: The whole point here is, there may in fact be some performance difference between physical USB ports on the MacBook, which has nothing to do with M-Audio. But more data is needed here. M-Audio had, along with other vendors, noted when there were USB audio problems on Leopard before, and that wound up going beyond just M-Audio.

    And another reason this isn't even a Mac vs PC issue — if there's a physical hardware issue here, you can bet that some PC laptops – which have similar logic boards – may have something related. 😉

  • @Adam: I think you're probably exactly right.

    So, given that both ports *are* powered, why the variation? (I hope we have a firm power requirement under the USB3 spec, but I haven't been following it.)

  • Jahmal

    This has been a well known discussion around the Native Instruments forums.

    MBP's have never liked my soundcards on the left.

  • makes me just want to hug my Motu 828 and firewire port close after hearing such things.

    Brian, if you're happy with it, then great. i'm not spend and evening rattling off my personal experiences and/or that of others in order to defend my disdain for M-Audio. let's just say, some, if not many folks have had problems M-Audio before. after a few experiences i formed an opinion to not buy their products.

  • @actuel: Right, that may be, but if we aren't specific about problems, there's not as much incentive to actually fix them. (I think that's the case here, too.)

    Of course, that goes both ways, so if the combination of powered 6-pin FireWire plus MOTU hardware works, then that deserves praise. Unfortunately, that combination is no longer possible on the new non-Pro MacBooks, meaning MOTU USB hardware is likely susceptible to just this issue.

  • Mattbot

    I've had quite a bit of audio trouble (random drops into full volume white noise, ouch!) with my Digidesign M-box using my MacBook Pro. I had chalked it up to driver problems but I haven't be able to duplicate the error on my Mac Mini. The M-box was always plugged into the left side USB port. I have done any testing do see if the trouble occurs with the right port.

    I've since upgraded my audio interface to a firewire Edirol FA-101 and it's been trouble free. I also like having one more free USB port for controllers.

  • I will say, I have an Edirol USB interface and NI Audio Kontrol 1. On my PC (right now an Asus), I have some four USB interfaces and have never had a problem. On my first-gen, non-Pro MacBook I've used both its USB ports.

    I know these issues can be hard to reproduce, but I'll at least say USB *can* work. The problem is, it can also get screwed up by the interface, the computer, the audio driver, the OS … so you do have to have all those pieces right, as with anything else.

  • Mattbot

    My above post should read that I have NOT done any testing to see if the trouble occurs when using the right side USB port.

  • Andreasfr

    Regarding M-audio products I think you get what you pay for and with M-audio often a little more (lovin' my axiom but playing my remote sl) that said, I have never been able to connect my tringerfinger to the USB port *closest* to the screen on my black MacBook. The port farthest from the screen works every time.
    Could this power-issue be related to poor recording performance in PT8 with my MBox mini? (Or does Avid's support for PT just kinda suck..?)

  • Mattbot

    @Andreasfr This issue shouldn't effect control surfaces like the Trigger Finger, only USB audio devices. I use my Trigger Finger on the left hand side of my MacBook Pro all the time without trouble. I suspect your issue has a different cause.

  • Dvice

    I have the same issue with Mac Pro front panel USB port with NI AK1, but no problem on my MB though, funny. Well, firewire is still the way to go.

  • kbooms1w

    The Audio 8 DJ eBook says just the opposite, use the left, avoid the right.

    11.3.4 Recommended USB-ports (MacBook Only)
    As a general rule of thumb, do not use the right hand USB port on a MacBook Pro: This port shares a USB root hub with the trackpad. With the AUDIO 8 DJ connected to the right port, you can encounter audio problems like clicks or dropouts whenever the trackpad is reactivated from standby mode.
    MacBook Pro recommended USB port(s)
    For the following laptops the use of USB audio devices on the right-hand USB port is not recommended:
    MacBook Pro 15” 1.67GHz Intel Core Duo and Core 2 Duo
    MacBook Pro 15” 1.83GHz Intel Core Duo and Core 2 Duo
    MacBook Pro 15” 2.0GHz Intel Core Duo and Core 2 Duo
    MacBook Pro 15” 2.16GHz Intel Core Duo and Core 2 Duo
    MacBook Pro 15” 2.33GHz Intel Core 2 Duo
    MacBook Pro 17” 2.16GHz Intel Core Duo and Core 2 Duo
    MacBook Pro 17” 2.16GHz Intel Core 2 Duo
    The 15” MacBook Pro models have 1 USB port on the left side, and one USB port on the right side.
    The 17” MacBook Pro models have 2 USB ports on the left side, and one USB port on the right side.
    Due to the current USB configuration of the MacBook Pro under OS X, use of USB audio devices is supported on the left-hand USB ports only (the port or ports next to the power adapter cable). Use of audio devices on the right-hand USB port is not recommended because it may cause audio interrupts and/ or dropped samples.
    However, the use of an iLok dongle on the right-hand port has been qualified and is fully supported.

    Am I reading all this wrong? I'm assuming they mean right and left as you face the computer, correct?

    I've been using the left hand one for a year and a half and don't remember having any drop out problems or anything, with Traktor Scratch or Ableton LIve.

  • Tim

    I found out this problem with my macbook when I had problems using my trigger finger. After a few key presses, the laptop would stop receiving signals from the TF. It was the strangest thing, and I thought it was a malfunction in the TF itself, and returned one but had the same result.

    I called M-audio, and they told me that the closer USB port shares power with bluetooth, keyboard, trackpad, and isight. This can be found in the About Mac under USB.

    Thus, I find it aggravating that I am unable to use more than one USB device because it may just stop working after a couple minutes without the use of a USB hub. Guess I'll have to get a firewire recording interface.

  • Rudi

    My M-Audio Trigger Finger only works for a few minutes on the left USB port on my 15" macbook pro. O2 seems to work fine, though. A friend told me a while ago about the power difference, so now I just use a hub on the right one.

  • Adam is correct. Apple totally screws one with underpowered USB ports.

    Hello RDF? This situation has existed/persisted for over 2 years. The advisories on m-audio's and digidesign's sites are *old*.

  • ps – i have an old Griffin USB hub that serves me well but it's not 2.0. The Dr. Bott powered hubs have always been tops. D-link makes a powered hub that is probably fine and much easier to find.

  • Hmm, worthy of investigation. I have had years of woe with USB on my 2006 MacBook Pro – external keyboard and trackball randomly disconnecting, USB HD suddenly unmounting, iSight coming and going, usually gear on one port followed seconds later by the other port, and then the first one again, …

    I've tried numerous makes of hub, all powered, to no effect. Perhaps it's this power problem on the left port, causing devices to reconnect and negotiate power, causing a momentary brown-out on the right port, and so on back and forth…

    I'd never trust audio over USB; FireWire all the way.

  • pierlu

    macs are not the machines they used to be. in the past they were more pricey that today (imagine that!), but were engineered like supersonic jets. it's simply not so anymore.

    i foresee more and more people turning to linux in the future running on non mac computers.

  • samu

    I'd seen the same informaton as kbooms1w from Native Instruments regarding the left port being recommended, and the same recommendation, opposite to that above, has come from Digidesign re: M-Audio interfaces in the past:…

  • That's very interesting to hear because I was having some kernel panic issues with a FastTrack Ultra USB a while back and contacted M-Audio support. They explicitly told me the right hand side port was to be avoided and I should use the left. They gave me a link to here:

    …and this page now says to use the right, not the left (as you say, Peter). WTF?

    Anyway, the problem was solved by just using a powered USB hub. Not ideal, but fine.

  • Zodak

    hmm, interesting. I can attest to having had numerous dropout problems with usb audio devices (i've had stuff from esi and m-audio) on my pc laptop. Sometimes just changing to a different usb port seemed to solve the problem. I too always thought it was some sort of driver problem but now it seems underpowered usb slots are something to look into. This may also have me rethink my plans to purchase the Mac Book (non-pro) I've been saving for…

  • cobaltage

    "Way back in 2008"?

    I've had a Fujitsu P1510 since 2005 or 2006, and the left USB port can't provide enough power for my generic USB SDHC adapter, while the right USB port has no problem. I figured it was because the power supply plugs into the right side or something, based on the comments of other P1510 users.

    USB has always been pretty sketchy for audio interfaces anyway. I've been disappointed that fullsize Firewire ports were never accepted for the notebook PC market, that Apple stopped supporting Firewire on the Macbook, and that the audio hardware industry has been pumping out more and more USB audio interfaces. I've actually been waiting for USB 3.0 before picking up another audio interface.

  • Mimmymabby! Mimmymabby! It's the Apocalypse coming!

    I (fortunately) never had to use usb audio devices, anyway I have several different usb peripherals and I noticed that both my 15" mbpro's ports supply a lot of power compared to my laptop pc. For instance, I have 2 different 2.5" external hard disks which are quite fast (that is, they also drain a lot of power) and both work perfectly with the mbpro while I get some "underpowering" error message on the pc so that they cannot operate correctly (continuously turning on and off).
    From specifications, usb2 must provide 5V (very important) at 500mA (less critical). Audio device manufacturers try to fit their usb devices with a lot of power-hungry electronics (like pre-amps) and these can exceed the actual amperage of the port. Indeed, internally a port can be connected to a usb hub which already reserves a certain amount of energy for some devices (e.g. a webcam). On Windows it's straightforward to see that in Hardware – USB controller – HUB.
    In other words the theoretical maximum energy supply of 500mA can actually be a lot less on some ports. I think this can be easily checked with a tester. No black magic.
    Anyway, keep in mind that a self-powered usb audio interface with 2 mic pre is already at the very limit of usb2 specs, so don't trust them too much. IMO manufacturers speculate a lot on affordable-democratic-self-powering usb audio devices.

  • Haven't noticed USB audio problems (but that's cos I'm using Firewire) but on my Lenovo PC laptop when connecting an external hard drive with a long USB cable to the right hand ports the drive will sometimes drop out. With no problems at all on the left hand port… A shorter cable fixes this but obviously there is some kind of power mismatch between the two.

    I've noticed power/dropout problems on other PCs when using firewire at the same time as cardbus adaptors too…I'm guessing some kind of bus sharing is the problem there.

    Still managing to make music despite the trials and tribulations though!

  • Joc

    Odd, my MB Pro only has USB on the left hand side. Does this only apply to older kit?

  • samu

    My problem with trying to avoid the iSight conflict is that on my (2006 2.33GHz 15") MBP, the AK1 and iSight seem to share the USB High Speed Bus whichever port the former is plugged into…

    Am I being a n008…?

  • It is demonstrable that firewire is better than USB for audio interfaces. The reason is that USB is a serial protocol, meaning that it cannot simultaneously write and read data. USB solves this problem via multiplexing, but that approach falls apart far too easily in a variety of situations.

    In high-bandwidth applications, like an audio interface where you have lots of data in, and lots of data out, you really need the asynchronous read/write access.

    That being said, there is really something horked about the USB on macbooks. I've never been able to get my line 6 toneport to work on anything other than a G4 mac-mini (but it IS rock-solid on that platform).

  • @plurgid: Yes, but by the same argument, a USB audio device that has lower bandwidth requirements, i.e., one with fewer channels, is perfectly fine.

    I don't really see this as a USB issue. If you starve any device for power and/or bandwidth, you'll have problems, regardless of the protocol.

    It sounds to me as though Apple compromised the reliability of one of the USB ports in order to reduce power consumption, right? (as opposed to providing a separate bus for these other peripherals)

  • Ben Allen

    Yes this is most certainly true. I first discovered this when I bought my 15" MBP with Core Duo and an Mbox 2 with pro tools. For some reason my shiny new macbook pro was absolutely terrible at rendering audio in pro tools and after maybe a month or so i finally figured out that it was because the Mbox 2 was plugged in the left USB. Then, later on the problem reappeared when I bought my Akai MPK49. I would plug it in the left USB port and I couldn't get the arpeggiator to work when it was synced to ableton. Lo and behold it was because there was not enough power going to the device. When I bought a power usb hub the problem is about 90% solved 😛

  • Another data point: a few months ago, USB completely failed on my MacBook Pro – no power, no nothing. Spent some time with a Genius-type-person in the NY Apple Store, and we discovered that USB worked fine with the MacBook battery removed. I now have a new battery, and it's still working, albeit with a couple of major wobbles per day (usually in the morning). So, the state of the battery clearly influences how well (or if at all) the USB ports function. So, possibly, does the state of the mains supply.

  • On every Dell and Gateway I've ever used, the front panel USB ports haven't had enough power for some devices, while the back panel ports are all fine.

    Powered USB hubs are the way to go.

  • I have this problem and it drives me crazy. I have a Motu Midi Express 128 and a Cubase 4 Dongle. The Midi Express has to be plugged into the right side and the dongle the left. That's it. No more USB ports. I find this quite limiting. USB expansion bays don't work so don't waste your money buying one like I did.

  • matt

    The left USB prot is the one I always use and never have issues with my AK1.

    The issue with the iSight is weird though. Sometimes it seems to be attached to the left USB, sometimes the right. I can fix the issue by plugging and unplugging in different combinations until I get it right.

    Additionally, my right USB port always has a Belkin 7 USB Hub with 3 controllers, hard drive, wireless mouse, and iLok…….never have a power issue overall with my 2006 MBP.

  • pyramind

    what about unibody mbp's? we have 2 usb ports and they are both in left…

  • zenzen

    This was definitely an issue on my late 2006 white C2D MacBook. The USB port closest to the user could not power an external 2.5" drive and would cause my edirol ua-25 to crackle and sputter. Kinda puts my newly acquired refurb MacBook Air in perspective. Just one USB port, but it's a good one!

  • eloise

    We've known about this issue for a long time.

    If you're using a Macbook where the USB ports are both on the left side, then use the USB port that is closest to the trackpad. Avoid the USB port closest to the power connection.

    I use a white 13" Macbook and I can confirm this is an issue with this machine.

    M-Audio actually makes some good products. Kudos for them for including the above advice very early in the game (compared to this post). They were letting us know about this issue over a year ago. Anyrate, the issue has zero to do with M-audio equipment; it has everything to do with the design and build of the Apple machines. Annoying.

  • marc

    Yup, my hardrive doesn't work with one of the ports on my macbook pro.

  • TJ Usiyan

    I have known about this since 2006. M-Audio has known about this since 2006 (i opened a ticket)

  • Well, sometimes we post the "News", and sometimes we post things "In The Order We Get To Them," so count this in the latter category. 😉

    I wish I'd known about this sooner. I did at least know that USB isn't always delivering the power it should.

    Actually just bought a USB bus-powered hard drive from Glyph with a novel solution: it has a y-cable for USB, so it sucks power out of two ports at once to make sure you don't run low. Fairly useless on most Macs, but it'll be handy on my PC laptop with four usb ports, because I can spare one (and can't spare FireWire while capturing from my FireWire HDV camera)

    But yes, the easy solution to *all* of this is to carry your AC adapter around. And that's been necessary even with some FireWire products.

    I love bus power, so I do hope this is better in the future than it is now.

  • the rule of thumb i heard was: the usb port closest to the power plug on one's macbook is the strong one and all others or at least the ones on the opposite side are the weak ones.

  • cobaltage

    The only reason IMO that this is a USB issue is that power issues in the real world implementation of USB are kind of pervasive. For instance, it frequently comes up that for desktop PCs, the USB ports on the front of the case often lack sufficient power for certain devices, like hard drives, requiring use of the (less convenient) USB ports on the rear of the case. But, at least AFAIK, 6-pin FW ports just don't have the same problems. I have never heard of any consistent problem with a 6-pin FW port not providing adequate power on any computer system, Apple or PC, notebook or desktop, front or rear, left or right, for a FW device designed to be bus-powered.

    A manufacturer of USB peripherals would point out that the amount of bus power available for a USB port is highly variable and beyond its control. But that's precisely a problem for USB as a real world standard if bus-powered USB devices can't rely on a given amount of power to run properly. We're obviously talking about bus-powered USB audio interfaces here; these devices typically don't ship with an AC power adapter or mains unit, because they are intended to be fully portable and hence bus-powered. But the M-Audio Firewire 410 shipped with a wall wart specifically because notebook PCs never have had 6-pin FW ports. (And the only reason that is is that FW ports were originally associated with video transfer, and video cameras have built in batteries.)

    IMO, when both notebook PC manufacturers and the audio computer peripheral industry went with USB 2.0 over standardizing 6-pin FW, that kind of killed off fully portable, relatively high-powered DAWs, at least for now. Not that it's impossible to put together something that works, but rather that you can't rely on things working reliably or at your convenience.

  • @cobaltage: I can't think of a specific case, but I believe there may be cases in which FireWire devices fail to receive ample power. But yes – perhaps partly because computer vendors generally aren't arbitrarily cramming more gear onto those buses, I would say FireWire power problems (using the 6-pin ports) are comparatively rare.

    Then again, 6-pin FireWire power ports are also known for frying camcorders when hot-swapped – perhaps the fault of poorly-designed camcorders.

    The front-panel USB issue you're describing I think is a different one, which is that sometimes those ports are designed to carry lower power levels. That is allowed under the USB spec, for use by keyboards / mics, which is presumably what the vendor assumed you would use those ports for. (I don't like the arrangement, but just saying.)

    In this case, these are *supposed* to be full-power ports, but in practice aren't.

    Not to be cynical here, but it seems to me that part of the problem is that the audio world isn't — can't be — as vocal as the much larger market for things like digital cameras, sadly.

  • cobaltage

    Also, Betamax was totally superior to VHS.

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  • What's lame is that M-audio either hasn't bothered to get out a voltmeter or load tester, and cite the results in their announcement. Just what the audio world needs – another piece of vodoo!

  • Matt

    Do this:

    1. Pull down Apple menu.
    2. Select About This Mac.
    3. Click the More Info… button
    4. Click on USB at the bottom of the Hardware list.
    5. Select the top USB Bus listed. It should already include the Bluetooth Controller

    Note that the bus has 500mA available. Note that Bluetooth requires 100mA. This bus is the the one next to the power input. Plug in a USB device, press Command-R to refresh the list, and see your device show up. It will list it's power demand. The Mbox will demand 500mA. If it shares a bus with Bluetooth turned on, there's 600mA demanded, only 500 available.

    Hope this helps some folks.

  • Mitchell Kehoe

    The Mbox tries to take every last drop of an entire USB bus?

    I think they need to just bite the bullet and ship an adapter with it, because 500mA out of MOST usb ports is a fantasy.

  • In the fine print of most USB interfaces, you'll see some mention of a use of even an optional AC adapter. And many do ship with an adapter.

    Rat– erm, Radio Shack, here we come!

  • chinese food

    My axiom doesn't even work at ALL on my macbook. Ports make no diff. totally fine on a powerbook, or G5 machine. all apps refuse to find it on the MB. I've tried everything, the macbook won't even look at it.

  • I can confirm this for the aluminum unibody macbook(discontinued) as well. I run my sound card on the right, controllers on the left

  • Marlon

    I have purchased multiple products from M-Audio from even when they were known as Midi Man to now (2×2 USB Midi-Interface back in 2000, Trigger Finger, 88 Pro ES) and have not had a single problem with any of my Equipment. I still continue to use my 2×2 Midi Interface.. Not knocking anyone's opinion, but definetly stand behind Midi-Man, M-audio, etc… until proven otherwise.

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  • Hey! Just thought I’d chime in. I really enjoyed your post. Keep up the awesome effort.