Motorola - PowerPC G4 (7400, 7410, 7450, 7451, 7445, 7455, 7457, 7470, G4Max, G4e, G4+)
This chip is the first PowerPC to include Velocity Engine (AltiVec) instructions. These instructions feature 32 separate 128-bit registers in hardware, and over 160 new instructions designed to process arithmetic operations commonly used in 3D graphics, image and sound manipulation among other things. Basically, AltiVec is planning to give Intel's SSE and AMD's 3DNow! instructions a run for the money. With its 160 instructions and 32 128-bit registers, it should be a worthy contender. Of course, game developers and Apple will have to rewrite their software to take advantage of these new instructions, so the performance increases will occur after new software arrives.

In multiprocessor formations, G4 processors can access each other's caches. According to Motorola, the G4 is manufactured on a .15 micron copper interconnect HiPerMOS fabrication process. IBM also produces G4 processors. Motorola had some problems producing G4 processors that ran at 500MHz. The problems were worked out, but by that time, Apple enlisted IBM to produce G4 processors. Even though the problem was fixed, yields of G4 processors over 500MHz are still low, and are expected to be low enough that faster G4 Macs will not be sold until sometime in Q3 or Q4 2000.

Motorola's G4e (G4-II or G4-Plus) with 256K of on-chip L2 cache, a 7-stage pipeline (opposed to the standard G4's 4-stage) allows for higher clock speeds, 2 extra integer pipelines (now a total of 4), supports 2 AltiVec instructions at the same time, and supports 64GB of memory (36-bit) instead of the 32-bit 16GB support of the standard G4. Should be a scorcher, but the competition will be fierce by the time it is released.

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