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I know FileVault is to encrypt files.
Will it slow down my Mac?
Can I use it on external RAID?


1. No
2. Use "it" meaning FileVault or Files encrypted by FileVault?

if {
FileVault
You can use it on USB and FireWire drives but not external RAID (at least i havent see something like this done beore ;)

encrypted by FileVault.
no. :)
}
 
I think saying it "won't" slow down you mac is a stretch. By virtue of the decryption that needs to take place it will be slower. That said, you may not notice with this version of FV. (It's really that good).
 
Thank you for the reply.
This is what I am doing, I have a RAID storage for my Time Machine and I also use it to put my downloads to it.
I don't want my kids to access to those files.
I mean I don't even want them to "see" my downloads.
 
Encrypting adds overhead, as the OS has to encrypt and decrypt data on the fly. Extra work = slower performance. How much that slower performance is the issue. From what I've read its not all that bad, but it can be a bit noticeable.

I'm not writing from experience since I don't use it, but extrapolating the fact its not a large performance hit based on posts/threads here and elsewhere on the net, plus various reviews of Lion in which they did reviews and benchmarks.
 
I had my internal and externals using FileVault and at times I noticed a slow down. My specs are 2.26GHZ C2D 8GB, so its not as if I had that bad of specs to begin with.

After some time I was worried that this was causing an issue, and disabled it. I've noticed no sluggishness like I experienced before.
 
The newest Intel CPUs have hardware AES built into them. But not the C2D. According to the Wiki link, Filevault 2 (Lion only) takes advantage of it. So encryption should be very very fast.
 
I know FileVault is to encrypt files.
Will it slow down my Mac?

It will slow your Mac some, depending on how old/fast your CPU is. Here is a test from Anandtech showing some benchmarks with and without Filevault2.

I use it on my 2010 iMac and notice no performance difference at all in day to day usage.

You can try it out and if you notice a slow down it is easy to turn off and go back to a unencrypted drive.
 
FWIW, I cannot tell a difference whether FileVault is on or off on my machine (early 2011 2.2 i7, samsung 470 256gb.)
 
I have FileVault 2 enabled on my 1.6Ghz C2D MacBook Air. It works fine although I didn't do any speed test.
 
On the newer macs, AES is accelerated in the CPU. No problem there whatever you do.

On older ones, it is possible to notice a performance decrease, but it's unlikely you will if you have a traditional spinning rust hard drive-- even the oldest mac that can run Lion's CPU is fast enough to encrypt and decrypt many megabytes per second of AES-encrypted data. Most hard drives, especially those in laptops, are unable to keep up with it.

Of course, if you're doing something with a lot of data that also requires a lot of processing, you'll find it a bit slower.

Also, if you do have an SSD, there is one other thing to look out for. Some SSDs, notably those based on Sandforce controllers, get most of their speed out of a compression and deduplication-algorithm. This algorithm can not work if you're encrypting the data before it goes to the ssd's controller. This slowdown, I can tell you, is noticable. So if you intend to use FV and are going to get an SSD, get one that does not base its performance on compression.


You can tell if your CPU does AES-NI by using the command sysctl hw.optional.aes.
 
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I know FileVault is to encrypt files.
Will it slow down my Mac?
Can I use it on external RAID?
FileVault 2(Lion and later) has a rather minimal impact on performance.

  • For the system disk, you enable FileVault from Security & Privacy (System Preferences).
  • For a Time Machine disk, you enable the encryption from Time Machine preferences.
  • For an existing disk other than system or time machine disk, there are command line commands to enable encryption without losing data. Read all popups to make sure you don't have an odd case that might cause it to wipe the disk.
  • For a new disk with no data, you can select "Mac OS Extended (Journaled, Encrypted)" as the partition format(file system) to use.
  • **Encrypting the disks takes a while, but has minimal impact during the encryption process. You can safely shutdown and sleep the computer or even unmount the drive and the encryption process will resume correctly. I recommend only encrypting one disk at a time.

And yes it can be used on external disks that are connected to the Mac.
 
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What if I use FileVault on a external RAID 5.
Saying one drive fail, will I have problem recover the drive?
There should be no issue recovering the drive. That's presuming that the RAID unit only has a problem with the one drive.

There is nothing in the encryption that would prevent hardware raid from working correctly.
 
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