I have a 1TB SSD in a 15" Mac Book Pro

It took about 30 hrs to Encrypt, which during, the computer was virtually unusable. It just finished with that and now it says it is optimizing with 5 DAYS!!!! remaining. I wish I never agreed to do it. Has anyone turned it off after the whole process is complete and if so how long did that take?

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    Why not just leave it on? It will take a while to decrypt your files and using FileVault increases your computers security. But if you really want to go to System Preferences, Security, then click FileVault. Then click turn off FileVault. – ajkblue Oct 30 '14 at 0:32
  • It sounds like there is something bad with your partition. On my MBP it takes approx. 1h for 750GB encryption. Try diskutil cs list in Terminal to see if encryption was successful. I had a similar case once where I decrypted / encrypted several times without success. Probably you should wipe your disk and reinstall. – n1000 Nov 6 '14 at 5:24
  • In my case it also took several days but with not performance impact. I did not notice any problem during the process. I have a 750 GB HD with over 500GB of data. – Matteo Jan 29 '15 at 7:54

Just go to System Preferences, click on Security, then FileVault then click the button that says turn off FileVault. But if you have it on, I would recommend leaving it on. It increases your security, and may take a while to turn off (decrypt) your files, but it's your choice.

  • I am just super bummed right now because of how long this is taking and how bogged down my mac is running. I have an important editing project to work on and everything is slow, and the optimizing is now saying 15 days to completion. I'm even thinking of rolling back to the last time machine I did right before I installed Yosemite. I wish there was some type of warning about this when they ask you to use FileVault. – Scott Oct 30 '14 at 2:32
  • Yeah that sounds terrible but from the looks of it all you can do now is wait. :( – ajkblue Oct 30 '14 at 4:41
  • I have even more ridiculous situation, Can you imagine "Optimizing 3532 days remaining", this is my way :) apple.stackexchange.com/questions/174108/… – Lu4 Feb 23 '15 at 15:53

I have a mac mini late 2012 with 1TB hard drive. There were 875GB free when I decided to turn off filevault 2 on Yosemite. It started at 9am and was done before 8pm. I checked disk activity from the activity monitor and it said about 975GB read/write at the end and the speed varied from 40MB/s to 20 or even 10MB/s at the very end. So, it seems like regardless how much space you have used, the OS will have to go through the whole disk read and write. My reason to turn it off was that it is my work computer and I think my office mates should be able to turn it off, turn it on, and log in with their account.

I'd like to add that the OS locked my keyboard when decrypting the harddrive. Plan the job accordingly.


MacBook Air with 128GB internal flash drive. Took about and 90 minutes to turn FileVault on. Taking so far 3 hours and showing another 5 hours to go to turn off. I can't imagine why it would take that long. I wouldn't mind but I was hoping to turn it off just for a few hours while I was doing stuff that involved restarting quite a bit. Wanted to set user to automatic login. I don't think I'll bother turning it back on after this. I know how to encrypt my private and important stuff and I have 2 back ups. One local and one time capsule at a different location. I think I'm covered.


I have a Macbook Pro 13" Early 2015 3,1 GHz Intel Core i7, 16 GB, 500GB SSD, macOS Sierra 10.12.16

I was experiencing severe speed degradation, CPU overloading, the spinning beach ball and forced reboots for several months. It primarily occurred during videos playing in Chrome or Safari, and during video conference calling, but also with other applications. I was avoiding having to do a complete reinstall of macOS.

I went through the list of potential causes and fixes here: http://machmachines.com/mac-slow-high-sierra-update-fix/

The last thing I tried was turning off FileVault. It took about 1hr.

After turning off FileVault, the problem is fixed, and my Mac is back to normal speed!


MacBook Pro (2.66Hz) 256GB SSD: estimated 2 hours, took 1:45.

That’s not counting time to make the estimate. That was around 2 hours by itself. The “estimated estimate” displayed while estimating the actual work time bounced all around. At one point it was estimating 1355 DAYS, but it stabilized on 2hr, which ended up pretty accurate.


NEVER EVER TURN ON FILEVAULT....WORST THING YOU WILL EVER DO. if something goes wrong in the startup process you mac will not turn on and you will need to call support. They will walk you through several steps and then have you turn it off. I just spent the better part of two hours doing this. And by the way you may lose the contents of your home directory during the decryption process..

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