I just grabbed and installed the 10.4.5 update off Software Update and it seems like the faster processor upgrades from Apple are not just for Mac Book Pro buyers. I may be imagining things, but my G4 iBook/933 seems to have a new lease on life. All of my applications are launching a lot faster. This is especially true on the second launch. I am not an expert, but to me Apple seems to have tweaked the caching a bit. Here is an example of what I noticed… on the first launch of Safari after the update it launched after 4-5 dock bounces, not a big deal. On subsequent launches however, it was up in running in under 2 bounces. AWESOME! The Dashboard exhibits similar behaviour. On the first hit of F12 it still takes a little time for my Widgets to initalize (but they do so about 3 times faster than before) and then on the second hit… BOOM they are there almost instantly. My scrolling everywhere is “like butter”, Expose does its swooshing acrobatics like a jet fighter, iPhoto screams and Spotlight searches are truly instant. It’s like I have a brand new iBook. Can everyone please tell me I am not dreaming. Am I just imagining things? Did Steve give me a virtual processor upgrade? Did some of those OS X for Intel optimization creep over into the PowerPC code? If anyone can enlighten us I would love to hear it, but for now I think this update to Tiger is the best ever.