Sonnet Technologies today introduced the “fastest single processor Macintosh upgrade ever developed” with the announcement of the new Encore/ST G4 1.2 GHz processor upgrade for the Power Mac G4. This upgrade utilizes the 745X series of Motorola G4 chips, has 2MB DDR (Double Data Rate) L3 backside cache, and delivers processor performance of up to three times that of the original systems. A complete list of upgradeable Power Mac G4s can be found in the press release. The Sonnet Encore/ST G4 1.2 GHz has an estimated street price of US$799.95.