The Power Mac G4 was a series of personal computers that was designed, manufactured, and sold by Apple between 1999 and 2004. They used the PowerPC G4 (PPC74xx) series of microprocessors. They were heralded by Apple to be the first personal supercomputers, reaching speeds of 4 to 20 Gigaflops. It was both the last Macintosh to boot natively into Classic Mac OS and the first to boot exclusively into Mac OS X.