Ever wondered why a Mac tends to have a slower clock-speed than a PC yet, tends to perform at or around the same rate? IE – I just bought a new Powerbook laptop and it’s got a 1.8ghz processor. I also just built a computer for my roomate that has a 2.8ghz pentium IV in it. They both have 512mb or RAM. Mine tends to run just as fast if not faster in some senses. I’ve bogged it down a few times by playing too many simultaneous tracks in GarageBand however. I can’t really speak from experience because my Alienware PC has over 1gb of memory and that wouldn’t be a fair comparison…but the Powerbook holds it’s own against the Alienware. I know most of you don’t speak computer very well, if at all, so I’m going to try and explain how a Mac with a 1.8ghz CPU performs as well as a PC with a much higher clock speed.

On a PC, a typical CISC (Complex Instruction Set Computer) processor has 100 to 500 instructions with up to 20 variations of each. It’s easier to program and require fewer lines of code.

Apple uses an RISC processor. The RISC (Reduced Instruction Set Computer) processor on the other hand, has mere 20 to 60 commands. But these commands require fewer clock cycles per instruction (CPI).

It is easier to build a CISC processor with a high frequency, and easier to program it. But a well programmed RISC processor will be faster than a CISC, even when running at less than half the frequency.

Hope that clears things up a little for people. If you understood it…

How does Apple address this issue? Publications like this. It’s a little old b/c it’s using some pretty old computers in the comparison, but it’s still very valid.