How long should I expect it to take to enable FileVault 2 on a fresh installation of Lion? I'm using a mid-2010 15" MacBook Pro with an i7 and a 5,400RPM 500GB hard drive with only 10GB used.

John Siracusa's 19-page review for Ars Technica had this to say:

Encryption happens transparently in the background, which is a good thing because it takes a long time.

Hopefully someone can be a bit more precise than this.

  • The new Airs with SSD are pushing up to 80MB/s of IO and less than 10% CPU while encrypting.
    – bmike
    Aug 2, 2011 at 15:50

6 Answers 6


You might find that the time taken relates to the size of the volume to be converted (not limited to the amount used).

Personal estimates of duration may be difficult.

Expect the most reliable estimates to be offered by System Preferences. If the system was only recently started, don't expect an accurate estimate of time; and don't be surprised if the estimate rises occasionally.

For more detail than is given by the progress bar in System Preferences: in Terminal you can run the following command, which will display a tree view of the CoreStorage world:

diskutil coreStorage list

Within the tree you'll see sizes; amounts converted.

If a volume is heavily used during conversion, it might slightly extend the time taken to complete but for your 10 GB used I would not expect there to be any difference. Use the volume as you normally would until conversion completes.

  • For me, this command showed None for both conversion progress and conversion direction (even after waiting for 30mins) until I rebooted my machine. I'm not sure if the encryption was progressing or not, but a reboot fixed the output of the command.
    – Ben Page
    Sep 3, 2015 at 13:03

2 consecutive vault activations on a 2 new MBP w 750gb drives. Each was a clean Lion install with nothing else on it.

Time to encrypt: 12 hours minimum each time. By far the longest running disk encryption on any platform I have ever used. Also, this is the only disk encryption I have used that allowed me to use the machine whilst it was grinding bits. I accept the trade-off.


Your mileage may vary, but it took about an hour to do on my clean Lion install (less than 10GB IIRC), Vertex 2 SSD. It'll obviously take longer the more data you have and the slower your drive.

  • I would presume even the zero data is changed so someone couldn't necessarily know whether a block had data or not when the decryption key was no longer present. This might be every bit as "expensive" to encrypt as real noisy data.
    – bmike
    Aug 2, 2011 at 18:06

Mine may be the "untypical" case. Upgraded my mid 2010 2.66 GHz i7 MBP 17" from Snow Leopard 10.6.8 (including the supplementary update) to Lion, then enabled File Vault on the 500GB internal HDD (14+GB free) and continued working. Took more than 16 hours -- continuous -- as I didn't turn off the MBP until it was done.


My personal experience is that it's faster than Bitlocker on Windows i.e. no more than 1 hour usually. Bitlocker on Windows usually takes several hours depending on drive size of course but even on small, fast raptor drive it takes forever. Encryption on Lion is painless in comparison, especially since it will run in background and even resume if you turn of computer. I don't have any benchmarks to back this up by I'm sure Ars Technica or Anandtech will come out with some soon.


On an early 2016 MacBook I got out of the box this week and on which I already have 30GB in use it said 30 minutes right at the start. It seems to be faster than that actually because I started answering this and now it's already down to 15 minutes.

Plus I can use it to do other things while it's encrypting.

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