Is Core 2 Duo Processor really faster than Pentium 4 Processor?

yes offcourse core 2 is really much faster than previous pentium processors.

Hi even i heard about that but the most important is how you configure you operating system to get optimum perfomence.But yes this is fact that core to duo is 40% faster then duel core(P-IV) but I am not sure about 40% energy saving.

Yes and yes. The 40% is at a minimum. Consider the difference in technology. Pentium 4 has hyperthreading which is a technology aimed to "mimic" multiple cores. Its still throttled at the same limitations as single cores even if it tries to manage processes separate of each other. The Core 2 Duo IS two processors, which will of course handle more workload. Picture a funnel and pouring water into it as fast as you can. That's the p4 and how it handles information. The core 2 is like having two funnels receiving the flow, thus doubling the amount that can flow through. As far as energy consumption goes, the p4 always pulled too much juice. It also had major heating issues specifically in the prescott series. The core2 architecture has been reworked to use less power and produce less heat. This will turn into a novel if I describe the changes so let's just leave it at, yes the core2 will destroy the p4 in terms of performance, energy consumption, and speed.