G4 processor upgrade purchased from
Other World Computing
(OWC) are compatible with Mac OS X v10.5 “Leopard,” according to the company.
NewerTech, an OWC subsidiary, announced Mondy that all NewerTech MAXPower G4/7448 Single and Dual Processor upgrades for Power Mac G4 systems have been tested and verified for use with Leopard.
Similarly, OWC announced that its line of Mercury Extreme-branded G4 processor upgrades are also compatible with Leopard.
Neither processor upgrade requires a software update or anything else to get working with Leopard — they should be plug-and-play compatible.