An interesting experiment with Intel processors fell 40% power consumption in Linux OS

The famous programmer and expert in Linux-kernel Matthew Garrett released the results of his experiment on activation of new mechanisms for saving electric power, embedded processors Intel Haswell and Broadwell. He was able to reduce the consumption of electricity of 8.5 to 5 W, thereby the time for an autonomous operation of mobile devices increases significantly.
Haswell processor architecture and Broadwell can not get into deep standby power consumption, if even one of these chipsets integrated subsystems (processor, graphics accelerator, PCH) is active. Platform Controller Hub (PCH) ensures operation of the input and output components, including USB and SATA. In Linux OS SATA interface is always active and processor can not Wesel in deep hibernation mode. Exactly the same is the situation in OS Windows, where to circumvent this problem using AHCI-drivers Intel. To solve this problem for OS Linux, the developer proposed to add small patch in Linux-kernel, which retrieves the appropriate settings at boot time kernel and adds two new policies for saving electricity. This experiment has not been discharged. Achieve even lower consumption through hibernation integrated graphics accelerator, where the content of the screen remains unchanged.