The CPU is just one part of the system. If you think performance is just the matter of the CPU, clock rate of such, then you are unaware of the effect shared video memory has on CPU benchmarks. Said shared memory video can cause a CPU to stall as the GPU (graphics chip) is accessing the shared memory.
Next is that battery life is driven down by the maker's and consumer's desire for lower costs. The moment you, as the designer find a way to double the battery life, the battery size is halved. This leads to two basic lumps or groups of battery life. The 4 plus hour portables and the hour or 2 desktop replacements.
And finally you have the screen size and brightness. When on the road I know to lower the brightness before I unplug so I save some minutes during bootup of power and only brighten it enough to use and don't over do it. The screen size matters since a 15" will, on average consume less power than the 17".
In closing, new CPU chips are going to show up in these few months so all the information will be outdated and not be usable for your decision process.
Bob
Does anyone know the url for the webpage here on CNET where different processors are compare for performance, price and battery life?

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