Apple's OS X Mountain Lion reportedly hindering MacBook Air 802.11ac speeds
One of the major upgrades found in Apple's latest MacBook Air is the inclusion of 802.11ac Wi-Fi, but a discovery on Monday appears to show an issue in OS X 10.8 Mountain Lion is hampering the laptop from reaching peak data transfer speeds.
In a review of the mid-2013 13-inch MacBook Air, Anand Lai Shimpi of AnandTech found real world 802.11ac file transfer speed to be artificially slowed by an apparent software issue in OS X Mountain Lion.
After finding speeds hitting a cap of 21.2MBps or 169.6Mbps over 802.11ac, much lower than the 533Mbps throughput seen with network testing tool iPerf, Shimpi narrowed down the problem to Apple Filing Protocol (AFP) and Microsoft's Server Message Block (SMB). Further investigation showed OS X does not scale TCP windows to the appropriate size, thus limiting the performance of the newly implemented 11ac protocol.
"The bad news is that in its shipping configuration, the new MacBook Air is capable of some amazing transfer rates over 802.11ac but you won?t see them when copying files between Macs or PCs," Shimpi wrote. "The good news is the issue seems entirely confined to software. I?ve already passed along my findings to Apple. If I had to guess, I would expect that we?ll see a software update addressing this."
A separate report from Ars Technica claims an 802.11ac-enabled MacBook Air running Windows 8 in Boot Camp will reach higher file transfer speeds than Apple's own operating system. While transferring files in Windows is relegated to Microsoft's SMB protocol, the publication saw speeds 9 percent faster than OS X over Ethernet, 30 percent over 802.11n and 218 percent faster on 802.11ac.
The issue also presents itself in the Developer Preview build of OS X Mavericks, suggesting the TCP limitation was not purposely instituted.
In a review of the mid-2013 13-inch MacBook Air, Anand Lai Shimpi of AnandTech found real world 802.11ac file transfer speed to be artificially slowed by an apparent software issue in OS X Mountain Lion.
After finding speeds hitting a cap of 21.2MBps or 169.6Mbps over 802.11ac, much lower than the 533Mbps throughput seen with network testing tool iPerf, Shimpi narrowed down the problem to Apple Filing Protocol (AFP) and Microsoft's Server Message Block (SMB). Further investigation showed OS X does not scale TCP windows to the appropriate size, thus limiting the performance of the newly implemented 11ac protocol.
"The bad news is that in its shipping configuration, the new MacBook Air is capable of some amazing transfer rates over 802.11ac but you won?t see them when copying files between Macs or PCs," Shimpi wrote. "The good news is the issue seems entirely confined to software. I?ve already passed along my findings to Apple. If I had to guess, I would expect that we?ll see a software update addressing this."
A separate report from Ars Technica claims an 802.11ac-enabled MacBook Air running Windows 8 in Boot Camp will reach higher file transfer speeds than Apple's own operating system. While transferring files in Windows is relegated to Microsoft's SMB protocol, the publication saw speeds 9 percent faster than OS X over Ethernet, 30 percent over 802.11n and 218 percent faster on 802.11ac.
The issue also presents itself in the Developer Preview build of OS X Mavericks, suggesting the TCP limitation was not purposely instituted.
Comments
Mavericks we have a bogey on our 3:00. Don't worry Goose, I've got him. Looks like a dated SMB protocol. Splash one old SMB Goose! Yeehaw!!! I'm going vertical with afterburners Goose!!! You are the best Mavericks!!!
And when it gets home safely, it can buzz the tower.
Quote:
Originally Posted by GadgetCanadaV2
Mavericks we have a bogey on our 3:00.
Roger, Gadget, I have your bogey.
Engaging...
Lining up for the shot...
I'm almost there...
10 more mbps then I've got him...
That said, I see a substantial perk to my speeds when going to Mavericks (from 19-20MB/s to 36MB/s).
From what I recall from WWDC, the indicated that Mavericks will still support AFP, especially when talking to AFP clients, but the default will be SMB going forward.
But the issue isn't AFP vs SMB; under either protocol, it appears OS X isn't achieving the expected throughput.
It appears the issue is a software TCP network setting in OS X that is not optimal when using 802.11ac wifi, preventing file sharing from benefitting from the extra boost in speed, making either protocol slower than it should be.
I never stated it was. I just stated that Apple was adopting SMB as the default starting in 10.9.
This is the last straw. I'm dumping Macs and OS X and moving to a real operating system. I just don't know what that is right now.
Apple will certainly fix this.
No they won't...ever...never...! Apple is surely DOOOOOOMED™ this time!
Me too! Even my Win'95 box was better than THIS!
What part of no, never or ever... do you not understand?!
Doomed I Say! :no:
/s
* Try this with a Windows RT tablet and all your dreams will...................???!!!! :rolleyes:
One thing that Apple does extremely well is networking software. After trying routers and software from various vendors, I ended up going all Apple and now enjoy extremely fast and reliable networking and almost never have to reset my routers. Compare that to the weekly and sometimes daily resets required of all routers from other brands. Also even though I have been a software developer for more than 30 years, I have never been able to get Windows networking to work correctly between different versions of that operating system or between Windows and Mac. It is like they are on completely different networks. This may explain why I am willing to give Apple the benefit of the doubt when it comes to their technical decisions.
Putting an APC between your router & the power outlet will usually fix the need to reboot often, unless your using linksys. I've had just about every type of router there is & find Netgear to be more reliable than Apple, but not by much. I use an AE for the Time Machine feature & iCloud support but now that Netgear has support for TM & it's own cloud sharing feature my future purchases may change.
As for networking, I'll take OSX over Windows any day for anything network related, for sure it is far superior to Windows in this regard.