G4 - technical definition

(1) (Generation 4) The fourth generation of a product, typically hardware rather than software.

(2) The fourth generation of IBM's CMOS-based mainframes (Parallel Enterprise Servers), introduced in 1997. See IBM mainframes and Parallel Enterprise Server.

(3) A series of Macintosh desktops and PowerBook portables from Apple that use the 32-bit G4 chip based on Motorola's PowerPC 7400. Introduced in 1999, G4 models were the successor to the G3 series and supported up to 2GB of memory, 64-bit PCI slots and 4x AGP. The G4 CPU included the "Velocity Engine," a vector processor that provides sustained floating point capability up to one gigaflops. See G5, G3 and Apple.