Is there any downside of encrypting my OS X 10.10.5 laptop via FileVault, in terms of usability?

Obviously, if I lose the password I can no longer use the laptop. (out of interest is that correct, will the laptop be completely un usable, or will the hard drive be unusable eg. if I were to swap out the HD for a new HD could i use the laptop again)

But apart from that would any other features stop working when the laptop was unlocked because it is encrypted (e.g. file sharing, printer sharing, Apple Remote Desktop, performance degradation, security issues).

I'm setting up the MacBook as new and debating turning on FileVault or not.

  • By encryption you mean FileVault I assume?
    – nohillside
    Mar 7, 2017 at 18:42
  • 1
    No downside other than the length of time it takes to do the encryption, (I'm assuming FileVault,) especially if the internal HD is a spinning disk, and/or if there is little free space on the drive. If there were usability issues, nobody would encrypt their disk. I have 4 Macs, all encrypted. I run Final Cut, Logic, Strata3d and other resource-intensive apps, and there is no degradation.
    – IconDaemon
    Mar 7, 2017 at 18:45
  • Have updated question re. Filevault
    – sam
    Mar 7, 2017 at 18:48

3 Answers 3


The implementation of Corestorage / Filevault2 is pretty great. That means you will hardly notice that your system is encrypted. I see the following points you may want to consider:

  • As you say: If you loose the passcode it is next to impossible to access your data.
  • There is a very slight performance hit because the CPU needs to constantly encrypt and decrypt your data. But moderns CPUs are optimised to do so and therefore the impact is negligible.
  • If your disk is corrupted or faulty in some way it may be more difficult to fix a corestorage volume than a standard HFS volume. Personally, this has never been a problem for me.
  • Passwordless boot or waking from standby is not possible anymore.
  • The most obvious difference is pre-boot authentication. That means you need to enter your password before the Mac boots up. Without encryption the system would boot and only require your password to log into an account.
  • Depending on your level of paranoia Filevault2 alone may not be enough. You should consider to also encrypt your backups (even higher risk for total data loss) and activate the option to destroy the password from RAM while the Mac sleeps.
  • 1
    Thanks @n1000, re. "Pre-boot authentication " is that when the machine starts from off ? Do you mean that it will take a longer to start from off / restart then it currently does when un encrypted ?
    – sam
    Mar 7, 2017 at 20:38
  • 1
    @sam No. Boot duration should be very similar. But you have to enter your password before macOS starts loading. Without encryption its is: macOS boots and you enter your password to enter into the account (if automatic login is not enabled)
    – n1000
    Mar 7, 2017 at 20:41
  • not sure im following then, your comment "Pre-boot authentication means you need to enter your password before you pick up your coffee in the morning while the Mac boots up." - Which part of the process is longer that requires you to wait while the mac boots up ?
    – sam
    Mar 7, 2017 at 20:44
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    @sam haha. l was trying to be funny. let me edit my answer. I was trying to say that the order changes. 1. hit power button 2. enter password 3. get coffee 4. start working. Before it was: 1. Hit power button 2. get coffee 3. enter password 4. start working
    – n1000
    Mar 7, 2017 at 20:47
  • yep, in macOS Catalina now, if FileVault is enabled, after logging in with password, a loading bar appears. It wasn't there when I did not turn on FileVault
    – cryanbhu
    May 29, 2020 at 22:38

You might get some performance degradation, but for what it's worth I've never noticed any.

You won't lose any functionality whatsoever. The only inconvenience I've run into is I can no longer reboot my Mac remotely (as I'd need my password to unlock it again). Other than that, it's been fine.

  • 5
    Take a look at fdesetup authrestart. That should allow you to bypass the pre-boot FileVault password on a per-reboot basis: osxdaily.com/2015/03/06/…
    – jefe2000
    Mar 7, 2017 at 19:08

Just wanted to add something because I was hindered by a change no mentioned above. It's not a deal breaker but knowing would have saved me a lot of time and worry.

  1. This may just be an issue with my computer; but when booting in recovery mode (holding 'option' at boot) I will not be given the built in recovery partition as an option. Instead I have to (hold 'command-r' on boot) to access it.

  2. When using disk Utility in Recovery Mode you are required to fist Mount the FileVault protected drive. Without doing so will return worrying errors that state unsuitability; instead of telling you to mount first, which would help immensely. It makes sense why since you are not required to enter the FileVault decryption password to startup from recovery OS, so disk utility has not been given access yet. To do so click the greyed out disk icon and click Mount.

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