I bought an external hard drive, plugged it into the USB port of my Airport Extreme base station, turned on Time Machine, set it to use that drive for backup.

It's backing up 350Gigs of data and it's literally taking days to work its way through.

Is this normal? It seems like it's taking a way too much time.

2 Answers 2


Over wireless, I'd assume less than 5gb per hour. More likely 2-3, putting your backup in the 5-6 day range.

Your best bet is to use an ethernet cable to connect to the Airport Extreme while the first backup runs. You should average 10+ gb per hour over a cable and I'd hop

  • Eh? Less than 5 per hour? Assuming even half of the theoretical max of 802.11n, 22GB an Hour. Those figures would only be even close to accurate with 802.11b. Granted, we don't know the specifics of the wireless the OP is using. Apr 26, 2011 at 6:12
  • @VxJasonxV actually we kinda do, he said: "USB port of my Airport Extreme base" so we can assume he's either using 11g or 11n (unless his iMac is really old). What we don't know is what number of files he has (zillions of small files could destroy that Wi-Fi). Yet his speed looks abnormally slow. I bet there's interference in his Wi-Fi. Apr 26, 2011 at 8:19
  • I've had the same experience. I'd definitely recommend using Ethernet for that first backup. Also, I've seen better performance on my machine using the 5GHz wifi band on my Time Capsule if you've got it and can't use Ethernet for some reason. Apr 26, 2011 at 13:41

350 GB is a lot of data, especially to transfer wirelessly. It will take a long time. In the future, only changed files will be backed up, so the backup will be much faster. To make the initial backup faster, you could try connecting the drive directly to the computer using the fastest possible port (see this question for a discussion of which ports are fastest). You will still be able to use the drive through the airport for future backups.

  • I don't think that the trick of "the fist backup" with the disk plugged directly on the computer will work. It seems that TimeMachine works differently if this is a networkdrive (Over the network, It's a dmg file that is used instead of the real volume) At least, that's my experience with my laptop.
    – Rabskatran
    Apr 26, 2011 at 10:48

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .