Using FileVault

ideal.dreams

macrumors 68020
Original poster
Jul 19, 2010
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I have a MacBook Pro with Retina display (specs in my signature) and have a few questions about using FileVault.

  • Is there any degradation to SSD speed?
  • Is there any degradation to the startup/shutdown time?
  • Is there any degradation to the overall speed of the computer?
  • Can I still use Time Machine to back up my data to an external hard drive?
  • Is it possible to disable FileVault after enabling it?

Thanks!
 

mrapplegate

macrumors 68030
Feb 26, 2011
2,818
8
Cincinnati, OH
I have a MacBook Pro with Retina display (specs in my signature) and have a few questions about using FileVault.

  • Is there any degradation to SSD speed?
  • Is there any degradation to the startup/shutdown time?
  • Is there any degradation to the overall speed of the computer?
  • Can I still use Time Machine to back up my data to an external hard drive?
  • Is it possible to disable FileVault after enabling it?

Thanks!
Nope.
Nope.
Nope.
Yes.
Yes.
 

ColdCase

macrumors 68030
Feb 10, 2008
2,963
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There is some impact to SSD data transfers, but you probably won't notice it unless you run a benchmark tool or do disk intensive video or photo processing. Startup and overall speed impacts you won't notice. Video encoding is just noticeably slower on my rMBP. Safe boot will not work.

You can disable file fault at any time and the OS will decrypt the entire drive for you (safe boot will then work).
 

ideal.dreams

macrumors 68020
Original poster
Jul 19, 2010
2,305
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Ohio
There is some impact to SSD data transfers, but you probably won't notice it unless you run a benchmark tool or do disk intensive video or photo processing. Startup and overall speed impacts you won't notice. Video encoding is just noticeably slower on my rMBP. Safe boot will not work.

You can disable file fault at any time and the OS will decrypt the entire drive for you (safe boot will then work).
I convert movies pretty often with Handbrake; is that slowed down at all?

Also are there any extra steps required to use Time Machine while using FileVault? And what happens to all of my previous backups without FileVault enabled?
 
Last edited:

ColdCase

macrumors 68030
Feb 10, 2008
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I convert movies pretty often with Handbrake; is that slowed down at all?

Also are there any extra steps required to use Time Machine while using FileVault? And what happens to all of my previous backups without FileVault enabled?
I don't think you will notice it, I think handbrake is more limited by CPU power. If too slow for you, you can always turn file vault off. FV will decrypt the drive for you and you are back to the pre FV config.

OS 10.8 file vault and TM works a bit different than previous iterations. Only thing file vault does is scramble data on your disk. For a TM backup, the OS unscrambles the files before sending them to your TM backup drive. The backup is unencrypted unless you also check off the encrypt backup in the TM settings.
 

Weaselboy

Moderator
Staff member
Jan 23, 2005
29,460
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California
I convert movies pretty often with Handbrake; is that slowed down at all?

Also are there any extra steps required to use Time Machine while using FileVault? And what happens to all of my previous backups without FileVault enabled?
There is some slow down in normal ops. and startup with FV2, but it is minimal. Here is a test showing with/without FV2 on.

Your TM backup will not be impacted by FV2.... it will just keep on going. If you are concerned about security, you may also want to turn on encryption for your TM backups.
 

ideal.dreams

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Original poster
Jul 19, 2010
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Ohio
I tried encrypting my Time Machine backups disk but it failed with the error that "The given disk is in use by a driver." Is there something I'm missing?
 

Weaselboy

Moderator
Staff member
Jan 23, 2005
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California
I tried encrypting my Time Machine backups disk but it failed with the error that "The given disk is in use by a driver." Is there something I'm missing?
That is a new one on me. I Googled that error message and all I could find were some reports of that message when turning on FV2? Are you sure the FV encryption was finished when you did this?
 

ideal.dreams

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Original poster
Jul 19, 2010
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That is a new one on me. I Googled that error message and all I could find were some reports of that message when turning on FV2? Are you sure the FV encryption was finished when you did this?
FileVault was definitely done encrypting my SSD when I tried to encrypt my backup drive. I had a movie running off of the drive so I'm assuming that caused the issue. I closed the movie, unplugged the drive to make sure nothing was using it and am trying it again. Hopefully that'll work.
 

ideal.dreams

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Original poster
Jul 19, 2010
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Do you have more than one partition on the Time Machine drive? If the answer is yes, that is the issue.
Nope, I haven't partitioned the drive. It's been encrypting for the last hour or so and it's only up to 6%. Is this normal? It's a 1TB drive.
 

Bear

macrumors G3
Jul 23, 2002
8,089
4
Sol III - Terra
Nope, I haven't partitioned the drive. It's been encrypting for the last hour or so and it's only up to 6%. Is this normal? It's a 1TB drive.
The initial encryption of the drive is done in such a way that it has minimal impact on performance if you are using the system while the disk is being encrypted. And that sounds about normal based on the last couple of disks I encrypted.

Note that you can sleep and even do a shutdown while the encryption process is going on. It'll continue the process when woken from sleep or started up.
 

ideal.dreams

macrumors 68020
Original poster
Jul 19, 2010
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The initial encryption of the drive is done in such a way that it has minimal impact on performance if you are using the system while the disk is being encrypted. And that sounds about normal based on the last couple of disks I encrypted.

Note that you can sleep and even do a shutdown while the encryption process is going on. It'll continue the process when woken from sleep or started up.
Is there a way to speed up the encryption of the disk?
 

ColdCase

macrumors 68030
Feb 10, 2008
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Does FileVault2 have any affect on the "wear levelling" on SSDs? does it lower its life?
No affect on wear leveling for the typical OEM drive apple uses. Most sandisk controllers take advantage of compression to achieve throughput and encrypted data is not compressible. So any throughput advantage those drive may have is mitigated. Since there may be more data being written you could postulate that there may be some additional wear, but I dunno if anyone has quantified the impact. Again only applies to those SSDs that use data compression. Otherwise it just bits and bytes.
 

Bear

macrumors G3
Jul 23, 2002
8,089
4
Sol III - Terra
No affect on wear leveling for the typical OEM drive apple uses. Most sandisk controllers take advantage of compression to achieve throughput and encrypted data is not compressible. So any throughput advantage those drive may have is mitigated. Since there may be more data being written you could postulate that there may be some additional wear, but I dunno if anyone has quantified the impact. Again only applies to those SSDs that use data compression. Otherwise it just bits and bytes.
Actually encrypted data can be compressed but it may not be compressed as much. And if you think about it certain types of datafiles (compressed image and music formats) can't be compressed much either.

All in all, I don't think using Filevault will have much extra wear even on SSDs that use compression.
 

ColdCase

macrumors 68030
Feb 10, 2008
2,963
142
NH
Actually encrypted data can be compressed but it may not be compressed as much. And if you think about it certain types of datafiles (compressed image and music formats) can't be compressed much either.

All in all, I don't think using Filevault will have much extra wear even on SSDs that use compression.
If the data is encrypted well it will look like a random set of unpredictable bits without any pattern that will not compress and be recoverable (although there are some theoretical methods). You can compress data prior to it being encrypted, however, and some FDE drives use that technique. Both video and music are not as random and could be brute force compressed a bit, but encoding is a better compression method for reducing their size.

The biggest reason some SSDs do not do well in a striped RAID environment is compression.
 

ideal.dreams

macrumors 68020
Original poster
Jul 19, 2010
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Ohio
So with FileVault enabled, what are the chances of data being recovered from the SSD should anything ever happen to my MacBook?
 

scaredpoet

macrumors 604
Apr 6, 2007
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You might also want to enable "Find My Mac" in the iCloud Preference pane. Although the location function is hit or miss (it requires WiFi be on and in range of hotspots, and won't work if WiFi is off and say, you're connected over ethernet), you can still do things like remote-wiping the mac if the data on it is something you're concerned about.

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So with FileVault enabled, what are the chances of data being recovered from the SSD should anything ever happen to my MacBook?
None so far. BUT, there's an optional backdoor that may cause you concern, depending on what you want to keep safe on that Mac. It's the security key that OS X offers to send to Apple, to unlock FileVault if the password is forgotten.

If you're absolutely paranoid about law enforcement or someone with social-engineering skills gaining access, then you will want to avoid sending the security key to Apple.