Other World Computing (OWC) today announced it has expanded its Mercury Extreme G4 AGP processor upgrade line with the addition of a 1.0 Gigahertz (GHz) model. The OWC Mercury Extreme G4 processor upgrades feature 256k of 1:1 L2 cache on-chip and 2MB of high-speed SPD or DDR L3 Cache operating at up to 267MHz. They are compatible with the PowerMac G4 AGP Graphics (Sawtooth), Gigabit Ethernet, Digital Audio and Quicksilver models and support Mac OS 9.2.1 and higher, as well as Mac OS X and higher. The new processor upgrade is available for $US349.99.