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Update: Mac Processors in 2020

Apple were forced to abandon the PowerPC processors, and completed the transition in 2008. I left this section here for the benefit of people who use vintage Macs, and because it is partly relevant for the next transition from Intel (CISC) processors back to a (PowerPC-like) RISC architecture of their own Arm-based processors, which Apple will soon start.

PowerMac Speed Information

The critical thing to remember when evaluating the speed of a Power Mac is that they run two types of programs: Power Mac native and emulated conventional Mac programs. Generally native programs are faster but to get the most benefit from the PowerPC architecture it is necessary to write programs a particular way - not all software developers do this really well.

Overall performance of a collection of PowerPC based Macintosh computers and some equivalent PCs. Performance measurement is notoriously difficult and real speed depends on many factors so this graph can only be used as a general guide.

To complicate matters system components which all programs use can also be either native or emulated because Apple hasn't ported all the system yet. So a fully native program can still run a lot of emulated code which will slow it down. As if that wasn't enough there are two major revisions of the emulator. The newer one, present in newer machines such as the 7200, is usually much faster than the original.

How to Make Your Machine Faster (Old Machines Only)

My first advice to Power Mac owners is "buy more memory". It doesn't really matter how much you have - you probably need more! In most cases 24MB will be enough but if you are running big programs like Excel, Photoshop or Freehand you should get more. I use 48MB and 32MB in my two machines which is enough for most purposes. When you get more memory turn virtual memory off. You will probably find at this stage that everything starts flying!

Update 2002. Wow, things have changed since I wrote that! Modern Macs should have at least 128MB, preferably more. I run many programs on my machine with 640 MB of RAM and under Mac OS X you never run out of memory!

If adding the memory didn't help you should check your software to make sure it is PowerPC native. There is usually a graphic saying "Accelerated for Power Mac" somewhere on the program's splash screen or box. If your program isn't native upgrade it--there are Power Mac versions of almost every program now. If you can't get a Power Mac version of the program try speeding up the emulator using Connectix' Speed Doubler system extension. As always be aware of the possibility of conflicts when installing a new extension.

Update 2002. For best performance under Mac OS X try to find programs designed specifically for it. There doesn't seem to be much advantage in using Cocoa or Carbon programs but Java programs will probably be a bit slow.

There are some programs which are just badly written and won't go much faster no matter what you do. Word 6 is probably the most obvious example. In this case you will either need to buy a faster machine, put up with the lack of speed, or use a different program that is fast (for example Word Perfect).

Comparison with Conventional Macs

So how fast are Power Macs when they are set up correctly? It depends how you measure speed. Running basic benchmark test such as Norton's System Info shows a typical Power Mac (I will use my 7200/120 with 48MB of RAM and level 2 cache as an example) to be 130 times faster than a Mac Plus! In extreme cases such as some floating point maths test the Power Mac is 35,000 times faster!

This graph shows an overall speed comparison of various current and older Power Macs compared with a selection of older conventional Macintosh computers.

Comparison with Other Computers

The RISC architecture used in the PowerPC chip which the Power Macintosh uses is generally more efficient and cheaper to produce than the conventional CISC used in the chips PCs use. Generally a PowerPC processor running at the same speed as a Pentium or Pentium Pro will significantly out-perform it. The big advantage with PowerPC is the relative ease with which really fast processors can be made in future. For example a 500 to 1000 MHz versions are being developed. The PC architecture is only surviving because Intel have the huge resources needed to keep their outdated design competitive.

In most cases PowerPC based machines will run real programs faster than their competitors. This especially applies to graphics and multimedia applications where Macs have a huge lead. Of course there are some programs where things aren't quite so good--Microsoft products for example, especially Word 6 where the PC versions are actually faster.