This can be true on modern CPUs as well. In fact, if the software chooses, it can even remove power from the core dynamically so one doesn't even have to pay t

This can be true on modern CPUs as well. In fact, if the software chooses, it can even remove power from the core dynamically so one doesn't even have to pay the leakage power. See for example Intel's C6 state. http://www.hardwaresecrets.com/article/Everything-You-Need-to-Know-About-the-CPU-C-States-Power-Saving-Modes/611 http://www.hardwaresecrets.com/article/Everything-You-Need-t...