|After test results from a number of new MacBook Air units that feature built-in 802.11ac support showed that speeds did not improve over 802.11n, Apple has allegedly invited some buyers to help test a Wi-Fi specific update for the machine that should eliminate what some have suggested was a hard-wired data cap on speed. While the problem does not affect all units, even a MacNN researcher experienced the issue. Apple has been swapping out new Airs at its retail stores in order to study the units that have the problem.
The issue affects the 11- and 13-inch 2013 MacBook Air, the first model to support the new 802.11ac standard, which is backward-compatible with older protocols. In theory, and in conjunction with an 802.11ac compatible router such as the latest Airport Extreme or Time Capsule, users should be able to reach network speeds as high as 1,300 megabits per second. Instead, testers have reported that while range is greatly improved, speeds are about half where they should be -- leading to speculation that Apple has inadvertently hard-wired an 802.11n limit into the OS or firmware.
Users who have received the invitation emails say they have not yet received the software, just the invitation, which also spells out some terms and conditions in order to qualify for the testing. Developers testing OS X 10.9 Mavericks and the next update for Mountain Lion, 10.8.5, say that they haven't encountered the issue, suggesting that both feature a new wireless stack that takes advantage of the 802.11ac standard more fully. Apple faced a similar issue -- and solved it in a similar manner -- when the first Retina display MacBook Pros appeared, reports AppleInsider. Some units initially had issues with 802.11n networks in the 5GHz band.