[clvv]

I believe the reason is memory latency, and the sequential nature of CPUs. http://en.wikipedia.org/wiki/SDRAM_latency

I'm no expert on this subject but I think Moore's Law is more or less still true, as we are getting more and more cores. Note that Moore's law never stated that clock speed doubles every 18 months. In fact, more transistor can cause a decrease in clock speed because of more gate delays.

http://en.wikipedia.org/wiki/Gate_delay http://en.wikipedia.org/wiki/Cpu#Clock_rate

Please correct me if I'm wrong.