After a post about Leopard slowing performance with updates I got this Bible about Tiger on the garden http://macintoshgarden.org/forum/tolerating-osx-starting-tiger Eyoungren has achieved a system with more headroom (even). " I removed the AudioIPCDriver.kext and that seems to have been a great help. Normally my Quad idleas around 6-10% of CPU. Now, it's idling around 2-4%. It's very low now. So, at least this has been a good benefit here. Going to try it on my other Macs." Let us use this post for the Tiger diggings we can find thru that lead.