HD Optimization and OS X

[Mobius Rex]

I've read/heard that with OS X, one's HD doesn't need optimizing unless it's got at least 85% of it's space filled, and that optimizing shortens the HD's life......the optimizing process is hard on it.
My TechTool Pro 4 manual says that it's a good idea to optimize "occasionally", but doesn't say at what point to do it.
I'd like the definitive answer on this matter. Anybody?

 

[Satcomer]

I stay away from the optimizing function of TechTool Pro. My OS X disk is already has been Journalize and that is more than enough to me.

 

[Mikuro]

I'm afraid there is no definitive answer. It depends a lot on how you use your computer and the specifics of your system. Many people will never need to defragment. Personally, I benefit from defragmenting some of my partitions every couple months. If you do video or graphics work, I recommend using a separate partition for it, and defragmenting that partition whenever you notice poor performance. That's the way I do it, and I never go out of my way to defragment my boot partition.

There's been a lot of discussion on defragmenting on these forums (see here and here for starters).