Migration Assistant slow using TB-USBC cable

Discussion in 'MacBook Pro' started by rudivd, Aug 22, 2018.

  1. rudivd macrumors newbie

    Joined:
    Feb 14, 2005
    #1
    Hi all,

    I got a brand new MBPro 15" 2018, While migrating using the USBC to TB2 adapter (Apple) and a TB2 cable (Apple) to my old late 2013 15" MBpro (in target disk mode), I was (unpleasantly) surprised that Migration Assistant gave me a speed of 10 MB/s while I was expecting something in the multiple GB/s range.

    Any similar experiences !? (Both machines had an encrypted APFS SSD)

    Any solutions !?
    Rudi
     
  2. RobbieTT macrumors 6502

    RobbieTT

    Joined:
    Apr 3, 2010
    Location:
    United Kingdom
    #2
    Multiple GB/s was never on the cards as the transfer cannot exceed the speed of the HD/SSD.

    The older machine uses the CPU to encrypt and decrypt data, so that will also slow the transfer of data.

    The cables and adapters add another source of confusion and this is probably the biggest bottleneck. USB-C is not Thunderbolt but a TB3 cable has a USB-C connector. Confused? It gets worse; even the USB-C cable that comes with your 4x TB3 equipped MBP is not actually Thunderbolt capable and will default to USB2 speeds. Best to think of it as a charging cable.

    Finally, MA is not just moving data as it is reinstalling software, plugins, settings et al.
     
  3. Fishrrman macrumors P6

    Fishrrman

    Joined:
    Feb 20, 2009
    #3
    This kind of thing (migration from old Mac to new) is better done using an external USB drive (USB3 is best), along with CarbonCopyCloner or SuperDuper...
     
  4. RobbieTT macrumors 6502

    RobbieTT

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    #4
    With a T2-equipped machine running a (currently) bespoke version of Mac OS?
     
  5. Painter2002 macrumors 65816

    Painter2002

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    Location:
    Austin, TX
    #5
    As other users stated, a USB-C does not necessarily mean you will get thunderbolt speeds, although personally 10mb/s does seem awfully slow.

    My guess is that the issue is part the adapter you may be using simply can't handle large sustained transfer speeds, and you also stated that both drives are encrypted so that may also impact the speeds (someone can correct me if I am wrong).

    My suggestion is the pretty much the same as @Fishrrman said. I don't have experience using Carbon Copy Clone, but I would use an external drive (if you have a large enough one), and copy your files to that from the old machine, then hook it up to the new MacBook Pro and use migration assistant that way. Additionally, if you already have a time machine backup of your old machine, you could just use that for migration assistant (this is what I typically do).
     
  6. Fishrrman macrumors P6

    Fishrrman

    Joined:
    Feb 20, 2009
    #6
    Robbiett asked:
    "With a T2-equipped machine running a (currently) bespoke version of Mac OS?"

    I don't see where this will make any difference at all.
    You're not booting from the cloned backup.
    You are merely "accessing it" using either setup assistant or migration assistant.
    Same as mounting any other drive.
     
  7. Howard2k macrumors 68020

    Howard2k

    Joined:
    Mar 10, 2016
    #7
    Please can you post pictures of the top and bottom of each side of each connector so we can read the labels.
     
  8. green86 macrumors 6502a

    green86

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    Location:
    North Carolina
    #8

    This. Also, You could try booting up migration assistant on your old machine and have it sit in the mode where is migrates from the machine...
     
  9. Arizor macrumors member

    Joined:
    Aug 24, 2012
    #9
    As @RobbieTT mentioned, the big bottleneck is the encrypting and decrypting process.

    I used Targetdisk mode on my first attempt, had your speeds.

    So instead, I backed up (Time Machine) on a USB-C SSD external (Samsung T-5). Then got speeds of 300MB/S.
     
  10. BLUEDOG314 macrumors 6502

    BLUEDOG314

    Joined:
    Dec 12, 2015
    #10
    Any AES-NI enabled cpu, which both of your machines have, can read and write encrypted data far faster than the interface can transmit it. That isn't your problem despite there being issues with apfs encryption speeds.

    Migration assistant sucks. I would bet if you do the same target disk setup and just drag and drop files from your old machine you will see significantly faster speeds.

    Further, the apple adapter you have is Thunderbolt 2 to Thunderbolt 3 and the apple cable is Thunderbolt 2, so you are limited by the slower protocol, not by USB speeds.

    I would just do a drag and drop and reinstall programs if you can.
     
  11. RobbieTT, Aug 23, 2018
    Last edited: Aug 23, 2018

    RobbieTT macrumors 6502

    RobbieTT

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    #11
    So which is it - using CarbonCopyCloner / SuperDuper or using Migration Assistant?

    Or if you mean both, why clone a device and then access it via Migration Assistant?

    I agree and that is what I ended up doing, but initially I just used MA from old to new as I didn't mind it running in the background and wanted to see what worked and what didn't as a way to test the new machine.

    This was an unnecessary step for sure, but it didn't cost me anything as it is a no-touch affair. After a few days of testing I wiped clean the 2018 machine and reinstalled the OS. I then removed anything from the standard install that I didn't need (some default apps, languages et al) before reinstalling only the essential apps from my old machine (ie another clear-out). The data was a simple and quick drag and drop via target disk, giving another opportunity to be brutal with what I needed on the SSD vs archiving or deleting.

    Whilst this left me with a cleaner and smaller installation (old 'system' files had grown to 60 GB, now down to under 14 GB) there was nothing wrong with the MBP after using the convenience of MA. Cleaning-house is somewhat cathartic though.
     
  12. Fishrrman, Aug 23, 2018
    Last edited: Aug 23, 2018

    Fishrrman macrumors P6

    Fishrrman

    Joined:
    Feb 20, 2009
    #12
    "So which is it - using CarbonCopyCloner / SuperDuper or using Migration Assistant?
    Or if you mean both, why clone a device and then access it via Migration Assistant?"


    I'd do it this way:

    1. When the new Mac comes, take it out of the box, set it up next to the old one, but DON'T turn it on yet.
    2. Connect my external backup drive to the OLD Mac.
    3. Open CarbonCopyCloner (one could also use SuperDuper, if that was one's backup software of choice), and run the "last incremental backup".
    4. Now, power down the old Mac and disconnect the external drive.
    5. Connect the external drive to the NEW Mac, and press the power on button for the first time.
    6. Begin setup. When setup assistant asks if you wish to migrate from another Mac or drive, "aim it" at the external drive.
    7. Select what is to be migrated and let setup assistant "do its thing".
    8. When setup assistant is done, it should present a login screen for the new Mac.
    9. Login and the desktop should look just as the old one did.
    10. Disconnect the external drive.
    11. Done.
     
  13. case2001 macrumors 6502

    Joined:
    Sep 9, 2010
    #13
    Will Migration assistant use a Time Machine Back Up? If so, what is the advantage to the above method vs a Time Machine Back Up?

    Thanks!
     
  14. Painter2002 macrumors 65816

    Painter2002

    Joined:
    May 9, 2017
    Location:
    Austin, TX
    #14
    I’ve used both methods (Time Machine backups and Migration Assistant) and I haven’t had any issues with either.

    The main situation where a Migration Assistant would be a better choice over time machine is whenever you are resting your computer and need to do a fresh OS install, for example if you experiencing a software bug.

    Using Migration Assistant will only import over your settings, applications, and files saved on the previous computer image, whereas a Time Machine is a full system backup and will restore everything including OS. This means Time Machine backups could have OS level bugs that will be reinstalled on your new machine.

    I could be wrong and someone please correct me if I am, but that is the understanding I have of the difference between Migration Assistant and Time Machine.
     
  15. deeddawg, Aug 24, 2018
    Last edited: Aug 24, 2018

    deeddawg macrumors 604

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    US
    #15
    Yes, it will use a Time Machine backup. See https://support.apple.com/en-us/HT204350

    I'm not sure there's a benefit one way vs the other, though if using a TM backup you wouldn't have anything that had been excluded from the backups so make sure nothing's excluded if going that way.

    Don't confuse this with Restoring from a Time Machine backup; that's very different from Migration Assistant using a TM backup as its data source.

    To clarify:

    Migration Assistant can read your stuff from your old Mac via Wifi or direct cable connection, it can also read your stuff from a Time Machine backup of your old Mac. You get to pick and choose what to bring over.

    Restoring from a Time Machine backup using macOS Recovery wipes the drive and restores the computer from the Time Machine backup. Not what you'd want to typically do with a new computer
     
  16. yukari macrumors 6502

    yukari

    Joined:
    Jun 29, 2010
    #16
    I moved contents from 2011 MBP to 2018 MBP using the same set up. My time machine HDD is TB1 connected.
    I had the same experience where the transfer speed was only ~10 MB/s.

    Now I know why as @RobbieTT explained usb-c cable that came with 2018 MBP is capable of only USB2 speed along with decryption process involved.

    I had no idea usb-c cable that came with 2018 MBP is only capable of USB2 speed.

    And why the he!! did Apple make TB3 connector the same as USB-C to confuse everyone???
     
  17. deeddawg macrumors 604

    Joined:
    Jun 14, 2010
    Location:
    US
    #17
    Yes, that's a definite failing. Many USBC "power" cables are just USB2 in terms of data transfer.

    Actual USB3.1 gen 2 capable cables exist such as https://www.amazon.com/Nekteck-Certified-Thunderbolt-Compatible-Delivery/dp/B0718Z1MWF

    Reminds me of the USB1 to USB2 transition where you had to be very careful what cable you used else your speeds were crap.
     
  18. haleyp macrumors newbie

    haleyp

    Joined:
    Jan 29, 2018
    #18
    My gripe is that there was no indication in migration assistant that my USB 3 backup would have been way faster. Now two computers are tied up for hours copying over 'thunderbolt' USB 2, with no desire to find out what untold horrors would accompany hitting 'Cancel.'
     
  19. green86 macrumors 6502a

    green86

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    Location:
    North Carolina
    #19
    There is no such thing as Thunderbolt USB2...
     
  20. deeddawg macrumors 604

    Joined:
    Jun 14, 2010
    Location:
    US
    #20
    I suspect he's referring to USBC "power" cables which support only USB2 data transfer speeds.

    Like the one Apple ships with their laptops. :rolleyes:

    As many pluses as there are to having a near-universal connector, the negative is you can't assume that different cables will all behave the same.

    It's been a while since I ran Migration Assistant. I seem to remember it had a progress / time-estimate during operation. Or am I misremembering? If so that'd be a pretty solid hint that the transfer wasn't going to be fast.
     
  21. haleyp, Dec 13, 2018
    Last edited: Dec 13, 2018

    haleyp macrumors newbie

    haleyp

    Joined:
    Jan 29, 2018
    #21
    Thanks for the reply. Yes, it had a time estimate, but not very helpful, it started at 36 hours but descended to 3 hours, but ended up stalling. The laptop connected via its charging cable but not to power had the plugged in symbol, but it was a lie. (I don't like the thought of two power supplies connecting the same system. However, I'd like to know if this is safe) After a 4 hours it still said about an hour but nothing had changed in the last hour and it said something like "this USB accessory couldn't be used." When I unplugged to try a different port the plugged in symbol changed to an empty battery. I cancelled the operation and my user had been created but nothing else transferred. It would have been nice to know the time machine backup was far more expedient. I don't even know how thunderbolt 3 transfer could work.

    However, in the meantime, my backup drive became unmountable and unrepairable after plugging it into my router. So now I'm trying to do another backup, but stuck on "Preparing backup" for the last 7 hours. I could use some more information, Apple. Is it stuck, or, should I stick with it?
     

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20 August 22, 2018