G4's (7400) with AltiVec arrives
Motorola calles the Vector Processor in the G4 "AltiVec" -- and Apple calls the same technology the "Velocity Engine". Don't let the names confuse you -- it is the same thing.
There are improvements over previous PPC's including:
Some people are reporting very modest increases by using the G4. But many benchmarks are not good at reflecting real world performance. For example, SPEC can't reflect some improvements because they don't even know how to handle an AltiVec (SIMD) -- so they show a 0% increase -- yet the real world performance could be substantial.
And more than just the processor performance increases, the G4s will go in systems (Sawtooth and later Shark) that are faster than the other systems of the day. The improved I/O of these motherboards, the maxbus, and so all this should all add up. So I expect that the G4 performance in a computer systems will be significant.
Rumors -- 64 Bit? Multicore?
There are 64 bit versions of the G3 and G4 in early phases of design -- but there is little reason to manufacture them right now. Likely we will see them with the G5 Processor (and a new core). Though there is nothing stopping them from adding them sooner -- it just makes more sense
There were some rumors of a processor (G4) with multiple cores -- but that was a while ago. The G5 is starting to come on the roadmap as well -- so I expect that multicore has been pushed out a bit to the G5 core. To see the benefits of multicore we need OS X shipping for a while and good MP support -- and it will likely be at least 6 months to a year after Apple starts selling MP boxes that we might see a processor that integrates multicore on chip. Apple first needs to prove the demand (and this guestimate is based on lead times, and how long it will take to get software polished and all that). So I expect it would be about a year after OS X -- which gives them enough time to come out with the G5 core first.
Of course, just to confuse things, IBM has released a new piece of "big iron" (S/390 mainframe) that they call the G5. They are even going to have the G6. I believe they use PowerPC's in this box, but only for I/O controllers -- the main processors are some custom high-end ultra-CISC chips. Not all CISC is bad CISC.
Motorola and IBM were diverging -- but it looks like IBM caught on to how neat AltiVec is, and they are coming back into the fold and going to probably make some G4 chips as well. With IBMs superior process technology, this should be good for all.
Change is constant, and progress will march on, while our computers get faster and faster. It is amazing that home computers of today are now performing like the supercomputers of a generation ago.
Apple is marketing the G4 as a "super-computer" -- which is true and not true. The AltiVec (Velocity Engine) Vector unit can compete in some ways with a Cray-YMP and other supercomputers of a decade ago (or even more modern) -- but todays super computers are massively parallel machines that can go up to Teraflops (trillions of floating point operations per second) instead of the G4s Gigaflops (billions). But most modern super-computers get their performance not by having a fast single processor, but with thousands of off-the-shelf processors (and complex memory systems and OSs). Intel and IBM have both made Teraflop computers (using Pentiums and PPCs respectively -- with IBMs machine being superior to Intels, as is to be expected). And these were made with PentiumPros and PPC 604s I believe -- imagine if they each did the same thing with newer processors!
Remember, they were doing amazing things with those supercomputers of 10 years ago -- and you can now do much of that on your desktop for 1:1000th the price. The individual G4 processor is certainly in the supercomputer range (for a single processor) -- but a single processing desktop machine isn't truly as fast as a brand new super computer, even if it is as fast as a super computer was just a few short years ago. So Apple isn't lying -- it is a super computer by export rules, and it is certainly performing faster (for some things) than most "super-computers" that are in most labs (unless they are very new supercomputers). And you can network an array of Apple G4 computers together, and get true (brand new) supercomputer performance at a fraction of the price -- as UCLA and some other places are doing. This is amazing stuff.
Of course home users really don't need to do the same things as super-computers (and their users) -- but there are many things that they do need a lot of computing power. What we users care about is not the speed itself -- but what the speed will allow us to do. Real-time photoshop filters, real time rendering, better video and compression, faster 3-D, better sound and speech (recognition) processing, better networking, and so on. Time marches on -- and computer technology just keeps getting better.