I am thinking of enabling FileVault in snow leopard.

I have tried to find some information regarding the performance, but have been unable to find any.

What are your personal experiences with FileVault?

  • 5
    I don't know about performance, but if you're using Time Machine then beware that it won't backup your FileVault folder unless you log off.
    – Arjan
    Sep 9, 2009 at 14:57
  • Maybe that's why I could never get Time Machine to work for me. It would crash and lock up the whole machine each time I tried to use it... Sep 9, 2009 at 16:57
  • 1
    It shouldn't crash; it just should skip your home folder... support.apple.com/kb/HT3446 -- You can turn on FileVault to encrypt data stored in your home directory. This data will also be encrypted in the backup. [..] When using FileVault, you cannot restore individual files in your home directory via the Time Machine browser. However, you can restore all files and folders by using the Restore System from Backup feature of the Mac OS X Installer. Important: Time Machine will perform backups only when you are logged out of your FileVault-protected account.
    – Arjan
    Sep 9, 2009 at 17:32
  • If any reader here uses FileVault 1 in Lion — and would like to benchmark (or at least describe their feel for things), both before and after abandoning version 1 in favour of version 2: answers under the following question will be greatly appreciated: Speed of old Filevault vs. new Lion full disk encryption. Note however that I do not recommend rushing to FileVault 2; see answers under apple.stackexchange.com/q/17889/8546 Aug 4, 2011 at 19:22

4 Answers 4


From what I have read, people have not seen significant slowdowns in performance. However, this does not mean there is not one.

http://www.oreillynet.com/pub/a/mac/2003/12/19/filevault.html This is a good article, but it does claim there is not really any performance problems and it is from when Filevault first came out 6 years ago.

http://www.oreillynet.com/cs/user/view/cs_msg/29494 This is a good discussion of the oreilly article. A couple users point out where he might be a little wrong about the performance claims. Again, this is really old.

Example of a secure delete taking a very long time with FV enabled. http://www.ehmac.ca/anything-mac/79222-filevault-taking-forever.html

http://al3x.net/2008/12/02/alternatives-to-filevault.html This is a good breakdown of some of the alternatives to FV out there.

I keep seeing mention of data loss issues, but I am not sure exactly what causes it. http://www.articlesbase.com/data-recovery-articles/interrupted-secure-erase-process-of-filevault-cause-mac-data-loss-955487.html


So, you are correct, there is not a lot of official talk on performance. I think it would really depend on the type of work you do on your machine and if you move a lot of data around. I think that is where you would see some performance degregation. Personaly, I don't think I would use it until I found more information on the issues people have had and learned "the hard way". Data loss issues would be a more serious issue to me then a little performance loss.

  • Interesting links, I agree data loss is a bit more serious than a performance hit! Sep 13, 2009 at 16:49

We use it to test at work and it doesn't seem any slower but we don't do much but write and browse the web with it. Make sure you have a good back up plan just in case you lose the password or your drive crashes/corrupts some how.

  • Same experience here, other than the occasional cleanup it does while shutting down. Even that isn't too much of a slowdown. Sep 9, 2009 at 15:00

I use FileVault on my MacBook Pro Unibody 2.5 GHz. During normal usage, I do not notice any significant performance problems. Large apps tend to take a little longer than usual to start up, but then again you don't start/quit apps that much in OSX.
Also, building projects in XCode tends to take a little longer, but you can set up XCode to build on a non-encrypted part of your hard drive, which solves that problem. Debugging also feels a little more sluggish, but not in a serious way.

So, I feel that there is a small performance deficit with harddrive-heavy operations, but overall it is seldomly noticeable. The one thing I would not recommend though is using a VMWare/Parallels virtual machine inside a FileVault. There you will certainly see a noticeable drop in performance.

  • 2
    If large applications start slower: did you FileVault your /Applications folder as well? Or do you have your applications installed in ~/Applications?
    – Arjan
    Oct 4, 2009 at 12:38
  • 1
    simply in /Applications. However, I suspect that there is a delay because of user settings that reside within the FileVault
    – bastibe
    Oct 11, 2009 at 14:26

I have done a little performance test a while ago with tiger:


Of course this doesn't say much about the SL performance (which might be better), still I think it's a similar direction.

Anyway, I turned it off after the experience with Time Machine only backing up stuff in your user folder when you are logged out. That's just total nonsense.

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