[tkmd]

I decided to put Leopard on a separate HD and have been running it for the past 3 months. I do video work so I routinely move large file back and forth. Past week I started to notice that the HD thrashed alot more than in the past. I still had 19 GB space left and could not figure it out- So I ran iDefrag and although the OS initially booted slowly (scary), apps didn't really open much faster but the amount of thrashing has been reduced significantly. Just wanted to post a positive experience if anyone else has a similar problem.

Funny, the thrashing never happened in Tiger so I don't know what Apple changed in Leopard...

[peeb]

[Big Mac]

19GBs free isn't a whole lot, especially with VM as a factor. People say drive speed begins to degrade when a drive is half full.

[peeb]

Yep - how large is the drive?

[Tomchu]

Drive speed may degrade because of the nature of circular discs and how much surface area passes under the head at the outer tracks compared to the inner tracks. :-P

The likelihood of fragmentation, on the other hand, goes up as free space goes down -- especially when dealing with large files. Fragmentation would be to blame for the thrashing.

[tkmd]

Originally Posted by peeb 

Yep - how large is the drive?

Its about 200 GB formatted. I know the ongoing argument for fragmentation on the mac, but after using this program I say the following:

1. large files (say over 2 GB, ie movies) seem to have gotten fragmented so when opening them the startup resulted in disk thrashing. Smaller files; idefrag did not make a difference.
2. I agree with the Apple document on disk fragmentation: no need to defragment, but I think Apple statement is geared toward the casual user who checks email, surfs the web etc.

Either way, todays HD are fast and compensate for HD fragmentation by their shear speed so its transparent to the casual user- but if your reading this, I suspect that your not the casual user.