Energy consumption
For the test on the CPU side, we were able to look at four models:
- Core i5-2300
- Core i5-2400
- Core i5-2500K
- Core i7-2600K
All these processors have a TDP of 95w and run at a power supply voltage of 1.2V by default, against 1.1V for processors in the S range which have a TDP of 65w. In practice, our Core i5-2500 runs very well at the clock and voltage of an S version, and then offers similar thermal behaviour. We tested them on an Intel motherboard, the DP67BG:
We measured the power consumption of the configuration at the wall socket of the power supply used, with a yield of around 80%. For the test in load we used Prime95. This means that other components such as the graphics card or the hard drive are in idle when these readings are taken.
Hold the mouse over the graph to see a classification of CPU’s by result.
Thanks to the 32nm process, the energy consumption of the new Core i5s and i7s is very well controlled.
Here now is the reading for power consumption at the ATX12V, using a clip-on ammeter. We haven’t given readings for the LGA 1155 CPUs as these results aren’t directly comparable from one platform to the other, on LGA 1366 for example the uncore part is powered from the standard ATX socket.
Intel has given itself plenty of margin with a TDP of 95 watts on these processors, and their actual energy consumption is a nice surprise in comparison to their specs. Because of HyperThreading, the Core i7 consumes a good deal more in load than the Core i5s.
