With the release of the Core2 Duo line of CPU, Intel has made a complete turn-around in their line-up, pushing the new party line of instructions per Watt. At first glance, primarily the lower speed grades are target for energy-efficiency claims for the simple reason that power consumption increases with frequency in a linear fashion. At close-up, the situation is quite a bit different since Intel's Enhanced Speedstep Technology throttles the frequency of the higher grades back to the same base frequency of 100 MHz while simultaneously lowering the supply voltage, thereby mitigating any potential savings of the lower speedgrades under idle conditions.