So basically it's "a dnetc client thing" after all? Because of all the other tests I ran it looks like PowerMac G5 PCIe 2,5 GHz is slightly faster (or slower) than 2,7 GHz Dual Processor (except from Quake III or MPlayer benchmarks, where it beats the AGP machine hands down), and then comes iMac G5 (albeit performing slightly better in 2 of 3 MPlayer tests than AGP G5), then PowerBook G4 1,67 GHz and the iBook G4 1,33 GHz always comes last.

EDIT: As for the AltiVec computations, here are lame_vmx results:

PMG5 PCIe: 39,804
PMG5 AGP: 41,864
iMac G5: 30,392
PowerBook: 17,977
iBook: 15,323

As you can see, the iMac is 70% faster than PowerBook despite only 25% faster clock. This is what I call a predictable result.

[ Edited by koszer 20.05.2020 - 15:35 ]