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?
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%5Fmsg/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.
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.
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.
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.
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.