Power Consumption in Nominal Mode
High performance is only one of the advantages of the new processors with Sandy Bridge microarchitecture. Processors based on it are considerably more energy-efficient than their predecessors. The LGA1366 platform, which is competing against Sandy Bridge, is, on the contrary, far from energy-efficiency. And even without the tests we understand that a Core i7-990X Extreme Edition based platform with its 130 W TDP will be much more power-hungry than the LGA1155 system with a Core i7-2600K inside, which maximum TDP doesn’t exceed 95 W. Nevertheless, it will be interesting to see how big the difference is in real tests.
The graphs below show the full power draw of the computer (without the monitor) measured after the power supply. It is the total of the power consumption of all the system components. The PSU's efficiency is not taken into account. The CPUs are loaded by running the 64-bit LinX 0.6.4 utility. We enabled all the power-saving technologies for a correct measurement of the computer's power draw in idle mode: C1E, AMD Cool'n'Quiet and Enhanced Intel SpeedStep.
Even in idle mode Core i7-990X Extreme Edition based system consumes twice as much power. The Intel X58 Express chipset also contributes to this situation, as its TDP together with the South Bridge equals 29 W. As for the LGA1155 system, it is one of today’s most energy-efficient systems for high-performance desktops, and Core i7-2600K fits perfectly into this concept.
The difference in power consumption is just as dramatic under heavy load, too. While we can’t tell definitively, which of the two processors - Core i7-2600K or Core i7-990X Extreme Edition – is the fastest, the Sandy Bridge CPU consumes 67% less power. And it means that we have an indisputable winner in terms of performance-per-watt.