Tomorrow, Motorola will formally unveil new technology for boosting the performance of PowerPC chips, taking the venerable chip architecture in new directions.AltiVec is two new technologies, one hardware, the other software. On the hardware side, it adds a new "execution unit" inside the PowerPC processor that is built to efficiently process certain kinds of data. All mainstream processors already come with execution units call "integer" and "floating point" designed to efficiently process other kinds of data.
The new "vector unit" operates concurrently with the existing floating point and integer units found in typical desktop PC processors.
On the software side, the chip will be able to use a total of 162 new instructions for manipulating data. This is of critical importance but with one major catch: Developers must write programs that use the instructions, and changes need to be made to the operating system to accommodate the instructions, said Turley.
In stark technical terms, PowerPC chips with this technology will be able to process 16 times the number of data "chunks" for each clock cycle compared to previous designs.
"Think of the chip as having a doorway in and out of the chip that's 32 bits wide, but the hallways are 128 bits wide," Turley offers. "Once data is moved out of [main memory] and into the chip, they can really swing lots of data around and do special number crunching, more so than other chips."
For instance, a single chip with AltiVec technology could run 30 28.8kbps modems in a remote access server (the kind a Internet service provider uses). This compares to a high-performance digital signal processor (DSP), which can run 8 modems, says Will Swearingen, product marketing manager for Motorola.
Motorola said the chip will initially be targeted at high-end networking and desktop computing applications, but will later find its way into lower-cost designs. The chip will be produced in sample quantities during the second half of 1998, with volume production slated for the first half of 1999.