Multiprocessing Makes Sense

Apple has claimed that the upcoming Mac OS X will support symmetric multiprocessing, so it came as no surprise that the company introduced a pair of dual-processor G4s at MACWORLD Expo in New York. What did surprise me was that these new models were actually replacing their single-processor predecessors, rather than supplementing them. For the record, the G4 line (not including the new Cube models) still consists of three models. At the low end is the single-processor 400 MHz model, priced at $1599 and now sporting a 20 GB hard drive. The dual-processor 450 gets a 30 GB drive, and runs for $2499. At the top of the range is the dual-processor 500 sporting a 40 GB drive and a $3499 price tag. Besides bigger hard drives and more processors, the only other changes to these models are the new mouse and keyboard, and the addition of standard gigabit ethernet.

This is interesting, because at these feature and price points, it makes sense for many customers to buy the dual-processor machines. The last time Apple offered a dual-processor machine (the Power Mac 9600/200MP in 1997), there were other high-end, single-processor alternatives available at much lower prices with similar features. Furthermore, the fastest Mac at that time sported a 233 MHz processor - which means that for most tasks, the cheaper single-processor model was actually slightly faster. Thus, the MP made sense only for those people who did a lot of work using the few applications which supported multiprocessing.

Now that the faster processors are only available in dual-processor configurations (Cube excepted), they provide a bigger performance gain over single-processor systems. Thus, the added cost is far easier to justify. Besides, you also get more RAM and hard drive space. Sure, you can "build your own" single-processor G4 to the same specs, but keep in mind that the majority of people donit buy from the Apple Store. Adding processors and leaving prices the same is a great thing for Apple to do; rather than paying for something you donit need, you are getting an excellent value. And while the Mac OS currently only has limited support for multiple processors, that will change once OS X has been released. As mentioned above, Mac OS X supports symmetric multiprocessing, commonly called SMP. This means that MP support is built right into the operating system. Thus, even if their code is not enhanced for MP, applications will greatly benefit from more than one processor. This means multiple processors wonit just be for people who do complex multimedia development; they will also benefit gamers, number crunchers, and programmers. While the multiple processor machine of 1996 and 1997 werenit very successful, donit expect the same of the new line of Power Mac G4s. Not only do these machines offer an incredible value, they also pave the way for one of the many benefits Mac OS X will have over the current Mac OS. Of course, things will only get better if Apple releases quad-processor G4s...

Oliver is a computer science student a the University of New Brunswick, in Fredericton, New Brunswick, Canada. He has been using Macs since 1986 when his father would bring home a Mac Plus on the weekends. He was one of the original writers for Webintosh, and before that was a contributor to the now-defunct MacSense CD magazine.