a small history lesson...
PowerPC, the architecture is derived from IBM's POWER architecture (Performance Optimized With Enhanced Risc). Apple approached IBM and got Motorola into the partnership to make PowerPC chips. It borrowed heavily from the POWER architecture.
The first ones were the PPC601, then the PPC603, and PPC603e. Then the PPC604 came along, which allowed multi-processor configurations. There is a PPC604e, IIRC. There is a bastardized one from Exponential, which never did pan out, but that was just a process change instead of any chip architectural improvements.
After this, the PPC750 came out, which is also known as the G3. There are still variants of these out since its a pretty good low power and decent performer. Along this time, the PPC7400 was in the works and its claim to fame is the addition of vector instructions to the PowerPC architecture. It was around this time that Amelio tried his hardest to crashdive Apple to the ground. At least, he made a good decision to bring el Stevo back.
This crash-diving made IBM antsy, and so they decommitted from the PPC7400 (G4). This left Motorola doing most of the development and bug fixes. When the iMac using the G3 took off, el Stevo was able to convince IBM back into the fold, but they were now behind. Since they decommitted, Motorola was not going to let IBM back in so easily. Here is where the bad feelings came in.
When the G4 came out, Apple convinced Motorola and IBM to play nice, and there were a few agreements signed, and IBM was back making PPC, this time the PPC7400 variant. Some of these actually came out into Macs.
IBM wanted back in, but Motorola likes being the only supplier of chips, so this left IBM playing second-fiddle. What they needed was a way to get back into the leap-frogging development style, since following Motorola's lead means that they will always be behind Motorola.
While all of this is happening, Motorola came out with the PPC7410, which was supposed to give the G4s a shot in the arm as far as clock speeds, but this was not to be. It did give a little lower power, at the same speeds, same power, at slightly higher speeds, but it wasn't the substantial clock speed increase. But it so happens that the PPC7450 was just around the corner anyway.
This was to be a 4 core processor. Similar to what the Power4 is, only with vector instructions that IBM thinks only makes a chip larger and more complicated. But the 4 core version was not meant to be. It was too expensive, and not suitable for placement into the inexpensive iMac and iBook. So, it had to go on a diet. First, it became a 2 core processor, and finally, became the single core processor that we know is the PPC7450.
The PPC7450 didn't get a substantial increase in speed either. It was larger, with 7 stage pipes, but it topped out at 733MHz. The PPC7400 with its 4 stage at 500MHz (PPC7410 at 550MHz).
So, as usual, the next chip is coming from Motorola, the PPC7455. This is the PPC7450 with a new process and a few tweaks, not a new architecture. So, this is where things sat until IBM finished working on the PPC970.
And this is where we are at now.
As to what the future will bring? I'm not supposed to say or else the people in the black helicopters are going to get me.
*shhhh*
What's that?
*CRASH*
NOoooooooooo! I swear I didn't say anything!
I know my rights, you can't make me do anything!
GET YER HANDS OFF OF ME, YA FILTHY APES!!!
