Processor Speeds

The clock speed of the cpus is only one of the components that determine the overall performance of computers. For each clock cycle, the cpu can execute instructions, but with each iteration of processor, they tend to become more efficient in what they can accomplish in that one cycle. Other big components of overall performance is the amount of on-die cache, size of the transitors (less distance travelled tends to improve performance), bus speeds, and ram speeds. One of the limiting factors of overall performance is how fast the cpu can push and pull data to the RAM, meaning bus speed and RAM cycle speed. Although CPU clock speeds stayed the same between early '08 macbooks and the alu macbooks, they actually increased the front bus speed speed from 800MHz to 1066MHz. The type of RAM used went from DDR2 667MHz to DDR3 1066MHz. They also put a significantly faster GPU in the new macbooks that should greatly improve their performance in Snow Leopard compared to last gen macbooks. Next year, more of the i7 chips will come out with similar clock speeds to now, but with significant performance gains over what we have now.

 

The front side bus of the newer CPU is key. That combined with the new GPU, it's a much more powerful machine overall.

 

You know that is why I don't notice that much difference between my G5 Powermac Dual Core and the new macbook.

Almost the same bus speed.