Designed around the Premise That Multimedia Will Be the Primary Consumer of Processing Cycles in Future Pcs, Altivec—which Apple Calls the Velocity Engine—increases Performance across a Broad Spectrum of Media Processing Applications. Altivec Extension to Powerpc Accelerates Media Processing

0272-1732/00/$10.00  2000 IEEE There is a clear trend in personal computing toward multimedia-rich applications. These applications will incorporate a wide variety of multimedia technologies, including audio and video compression, 2D image processing, 3D graphics, speech and handwriting recognition, media mining, and narrow-/broadband signal processing for communication. In response to this demand, major microprocessor vendors have announced architectural extensions to their general-purpose processors in an effort to improve their multimedia performance. Intel extended IA-32 with MMX and SSE (alias KNI), Sun enhanced Sparc with VIS, Hewlett-Packard added MAX to its PA-RISC architecture, Silicon Graphics extended the MIPS architecture with MDMX, and Digital (now Compaq) added MVI to Alpha. This article describes the most recent, and what we believe to be the most comprehensive, addition to this list: PowerPC’s AltiVec. AltiVec speeds not only media processing but also nearly any application in which data parallelism exists, as demonstrated by a cycle-accurate simulation of Motorola’s MPC 7400, the heart of Apple G4 systems.