Giga Designs is now shipping a 1.5GHz G4 processor upgrade card for Apple’s Power Mac G4 Cube. The new “M series G-celerator” uses the latest G4 (7457) processor available from Motorola, offers power consumption that is up to 1/3 less than that of previous G4s, and has a larger (512KB) on chip L2 cache. The company says the US$599 upgrade also features new “PowerShare” architecture, in addition to the original adjustable speed and voltage settings, which gives users the ability to maximize the Cube’s performance while allowing for high performance graphics and storage devices.