Software Slowing Some Wi-Fi File Transfers on New MacBook Air

Discussion in 'Mac Blog Discussion' started by MacRumors, Jun 24, 2013.

  1. macrumors bot


    Apr 12, 2001

    Networking code in OS X Mountain Lion is slowing down file transfers over the Apple Filing Protocol (AFP) and Microsoft's Server Message Block (SMB), according to examinations done by both Ars Technica and AnandTech.

    The issue affects the new MacBook Air models that come equipped with the 802.11ac Wi-Fi technology. The new MacBook Air and Apple's new AirPort Extreme base station are the first Apple products to use the new Wi-Fi technology.

    Anandtech discovered that the TCP window size for file transfers in OS X was too small to reach the potential throughput on many file transfers, slowing data transfers from a potential 533Mbps down to 170Mbps.
    Ars Technica confirmed AnandTech's findings, and went a bit further. The site discovered that when running Windows 8 in Boot Camp, the new MacBook Air saw file transfer speeds significantly higher than under a comparable setup in OS X Mountain Lion.
    Ars' OS X wireless setup saw transfer speeds of 21.71MB/s on SMB, and 47.26MB/s on a comparable Windows 8 setup under Boot Camp.

    The issues also exist under the developer beta of OS X Mavericks, but both sites expect Apple to release a software fix for OS X that will solve the file transfer issues.

    Article Link: Software Slowing Some Wi-Fi File Transfers on New MacBook Air
  2. macrumors 6502

    Apr 26, 2011
  3. macrumors 6502a

    Oct 3, 2012
    Darn I still want an ac device for my new time capsule! I wanna see what the fuss is about when its put to its proper power!
  4. macrumors 68040


    Jun 26, 2009
    Burpelson AFB
    Not a big surprise. New hardware often has driver/software problems. No need to return new MacBook Airs. They will be fixed in a software update ;)
  5. macrumors 604


    May 28, 2005
    In other words, a typical 1st revision Apple product.
  6. macrumors 6502


    Nov 14, 2007
    One would still think these issues should be more uncommon on Macs than they are since ”Apple makes both the hardware and the software”, no?
  7. macrumors 65816


    Oct 31, 2006
    Haha the delusion of integration! It took a third party for Apple to do their testing and analysis for them after the product release. The Windows part gotta hurt the fanboys real bad :)
  8. macrumors 68020


    Nov 18, 2010
    Nothing beats good ol' GigE. :p
  9. macrumors 601


    Feb 22, 2003
    New Hampshire
  10. macrumors 603


    Jan 8, 2009
    How quickly things change (sigh) :eek:
  11. macrumors 68030


    Disappointing, but no need to panic. Now that awareness has been raised, it'll be addressed in a future software update.
  12. macrumors demi-god


    Aug 17, 2007
    Seattle, WA
    One would think these would have been caught in testing and development, however...

    Unless they were all on a special "802.11ac" build of 10.8.4 that was meant to be released with the MBA, but for some reason was not (or perhaps testing was done on 10.8.5)?

    As noted, I expect 10.8.5 will fix it or there will be a special patch of 10.8.4 for MBA users.
  13. macrumors 68030

    Oct 9, 2007
    For all we know, it's already been taken care of in Mavericks.
  14. macrumors 6502

    Nov 2, 2010
    Wow. I do a lot of Mac-to-Mac, Mac-to-Windows, and Windows-to-Windows transfers. Mac-to-anything transfered always seemed slower to me but I always thought I was imagining it. Am feeling disappointed now with the Mac's performance here. 30% over 802.11n is a large difference.
  15. macrumors 68040


    Jun 26, 2009
    Burpelson AFB
    Yes, one would think that. Despite owning the stack Apple still has its share of problems.

    Unfortunately the problem also is in the Mavericks developer preview :eek:
  16. macrumors regular


    Apr 30, 2005
    "Windows is, at best, about nine percent faster over Gigabit Ethernet and 30 percent faster over 802.11n, but it's 218 percent faster over 802.11ac."

    Unacceptable for any protocol. Apple needs to correct this. There is no reason that a Unix based OS should be slower than Winblows in file transfer speeds.
  17. macrumors 6502


    Oct 28, 2007
    Denver, CO
    One case = delusions of integration
    Hundreds of cases of fail because of lack of integration = ???

    I think you need to return your logic unit, it appears to be the old Pentium 100 type with the math error in it.
  18. macrumors 68030

    Oct 9, 2007
    OK, how about "For all we know, it's already been taken care of in Mavericks Preview 2"? :eek:
  19. macrumors 6502a


    Jan 25, 2011
    But dude, you don't understand - wires are old fashioned and wireless is high tech and modern! /s

    In all seriousness, did they benchmark Thunderbolt -> Ethernet connector on the MacBook Air?
  20. MikhailT, Jun 24, 2013
    Last edited: Jun 25, 2013

    macrumors 601

    Nov 12, 2007
    Integration doesn't mean there wouldn't be bugs. This is a software issue that can be fixed in a future update. It only affects SMB/AFP. The rest works fine.

    It hasn't been fixed in Mavericks according to Anand.

    It's just a bug in the TCP window sizing system for both AFP/SMB stacks. It's not resized to 256KB properly. Once they fix the bug, it'll just be normal fast.
  21. macrumors 65816

    Aug 13, 2011
    Don't be silly. Ever read the non-iOS cell forum? True fanboys will defend it no matter what ... Watch this space :p
  22. macrumors 601

    Mr. Retrofire

    Mar 2, 2010
    Replace “product” with “driver”. :D
  23. macrumors 65816


    Aug 29, 2009
    I'd think one would think that, since Apple makes both, they can deal with the problem quicker than if they didn't have that control...
  24. macrumors 65816


    Oct 19, 2012

    being a software issue, that can be fixed via a Software Update. Dont like a shinny piece of software with network bottlenecks......:mad::eek:

  25. macrumors 6502a

    Aug 3, 2010
    Upstate NY
    No it won't it says right in the article that transfers are slower on OSX and that isn't the particular issue here. Resizing the window is only going to get it up to normal levels of slower than Windows, not up to Windows speed.

Share This Page