Benchmarks are a great way to illustrate performance.
Here is a comparison chart that clearly shows the performance advantage that Apple has over its Windows-based competitors. Adobe Photoshop, a leading design application, is great for performance comparisons, because it runs on both Mac and PC platforms, and is very processor intensive. The bars in the graphic above indicate the number of seconds required to perform a specific sequence of Photoshop actions. Shorter bars indicate faster performance. The results show that the new PowerBook systems perform up to 30 percent faster than several leading mobile Pentium III-based systems at 500 MHz.