Quoting CK x@meta.lo-res.org:
a lot of programs have intel assembly optimizations but not altivec.
and of course linux runs a lot faster than osx.
That's completely contradictory information, and the latter statement is patently false. Perhaps you meant to say that some Linux window managers draw windows faster on your old powerbook compared to OSX on the same hardware? OSX takes more and better advantage of available hardware resources like SIMD and 3D acceleration than any consumer OS I've ever seen. Run GEM on a G4 in Linux then OSX, the performance disparity will be huge, and not in favor of Linux. The reason why PPC Linux isn't a smart choice on recent Macs isn't because they are both Unix based OSes - it's due to the fact that you basically throw away nearly all the hardware advantages you paid for when buying the Mac!
cgc