Other World Computing announced today that it has started shipping the PowerLogix PowerForce Series 100 1GHz G4 upgrade for PowerMac G4s (350MHz-500MHz AGP-based) and G4 Cubes. The 1GHz upgrade is priced at US$789.95. The PowerForce Series 100 G4 upgrade is also offered in 700MHz ($445.99) and 800MHz ($589.99) versions, slated to ship in 2-3 weeks.