Until recently, Omniweb 5 was running significantly slower on my G5 than my lesser spec-ed G4 Powerbook. It was snappy on the powerbook, but sluggish on the G5. Both machines have near-identical files, as they are daily kept in sync with Chronosync. I couldn’t see how the better spec Mac was so slow.
After a post I made to the Omniweb Mailing List about this, the culprit was found to be Spotlight. There seems to be a known bug, whereby OS X can can forget privacy settings for a removable firewire drive. Therefore, every morning when I attached my powerbook to my G5 via target disk mode for syncing, the system would start re-indexing the powerbook.
Stopping the indexing resulted in a much happier G5, and in particular the apps that were using the most CPU - Omniweb and Fireworks.
I’ve seen a few suggestions bandied about for this - but most involve disabling spotlight altogether. I actually find spotlight rather handy, so would prefer to keep this on. Another suggestion involved adding the drive name to a hidden preference file, but ‘Macintosh HD’ could cause some problems there.
If anyone has discovered a way around this - please let me know!