Slow AirPort speeds? Try changing wireless security

you are having issues with slow network throughput, you may want to try changing the security protocol in use.

In some cases, WEP key-based access can provide better speeds when compared to the more secure WPA standard.

This setting can be changed on AirPort base stations by using the AirPort Admin Utility (located in Applications/Utilities) to configure the target base station.

One MacFixIt reader writes:

"I was having (slow AirPort throughput). Not knowing what system change caused it (I am running 10.4.5 and the latest security update), I tried reverting the AirPort Extreme firmware to an earlier version (I am running firmware version 5.7 only in 802.11g mode). No firmware downgrades accomplished anything. I was seeing nearly an hour to copy a 100 MB disk image from a 12 inch 867 Mhz PowerBook with all software updates applied to a G4 iMac 1 GHz also with all updates applied. On a whim, remembering the performance hits earlier Graphite Base Stations took when wireless security was turned on, I turned off all WPA2 Personal wireless security on the AirPort Extreme Base Station. Whoa! Network speeds were back to normal, with the 100 MB disk image only taking less than a minute to transfer. Not wanting to run exposed, I tried turning on just WPA, not WPA2 and network speeds were slow again. So I took the Base Station down to WEP 128 bit, and speeds were back to what they were supposed to be. So you may want to try downgrading your wireless security just to see what happens. It worked for me. 

"Something has obviously recently changed with the latest OS X updates, as I had never seen this previously using WPA2 or WPA. Now my network can only achieve good local data throughput between machines using WEP 128."

For more suggestions on improving AirPort throughput, see our tutorial "Improving AirPort reception, avoiding dropouts/lost connectivity, working around card/Base station recognition issues."