Latest developer notes on the (still beta) next version of OS X, codenamed "Leopard", used to say that it's for "an Intel processor or a PowerPC G4 (800MHz or faster) or G5 processor", according to AppleInsider.
Now, apparently, that's been moved up to 867MHz.
Why the exclusion? Ran too slow on machines below that. Which you can understand: it gets harder to get comparatively slower systems to perform some of the video (especially) and CPU work snappily enough to give a satisfactory user experience.
AppleInsider again:
Though seemingly mild, the 67MHz increase [from the previous lower limit] will exclude a handful of Mac system, namely the 800MHz PowerBook G4 (Titanium), 800MHz PowerMac G4 (Quicksilver), 800MHz iMac G4, 800MHz iBook G4, and 800MHz eMac.
However, according to this page from the (unofficial) Apple Museum (which seems itself to have headed towards the site museum), Apple sold a machine - the eMac - that ran at 800MHz until October 2003 - when it also phased out G3-based iBooks to replace them with the (800MHz) G4 iBooks.
So, is four years long enough for an operating system's life? In that period, anyone who bought one of those machines would have upgraded to Panther (10.3) and in April 2005 to Tiger and now has the chance to chug on with Leopard. That's not bad for some ageing kit, is it?
Meanwhile, there are already rumours that the successor to Leopard - 10.6, as yet no codename - won't work on PowerPC-based Macs. But there's probably not much reason to worry on that score. By current progress, my guess is that 10.6 won't be troubling our doorsteps before 2010.
