The Velocity Engine, embodied in the G4 and G5 processors, expands the current PowerPC architecture through addition of a 128-bit vector execution unit that operates concurrently with existing integer and floating-point units. This provides for highly parallel operations, allowing for simultaneous execution of up to 16 operations in a single clock cycle. This new approach expands the processor's capabilities to concurrently address high-bandwidth data processing (such as streaming video) and the algorithmic intensive computations which today are handled off-chip by other devices, such as graphics, audio, and modem functions.The AltiVec instruction set allows operation on multiple bits within the 128-bit wide registers. This combination of new instructions, operation in parallel on multiple bits, and wider registers, provide speed enhancements of up to 30x on operations that are common in media processing.
|