Linux 3.1 Kernel Draws More Power With Another Regression
If you were hoping that the Linux 3.1 kernel would fix the big power regression problem that's caused by PCI Express Active State Power Management (ASPM) being disabled on more systems since the release of the Linux 2.6.38 kernel, you're not in luck. There has not been any active work in this area. Making things worse though for mobile Linux users interested in a long lasting battery is another new regression in the Linux 3.1 kernel. Affected systems can easily see a 30% increase in power consumption simply when comparing the Linux 3.0 kernel to the current code being assembled for Linux 3.1. For an Intel Sandy Bridge notebook, the power consumption is up by 76% just over the course of this year from Linux kernel regressions.
Besides the new Linux 3.1 kernel power regression, there's also a power regression introduced in the Linux 3.0 kernel that has previously not been talked about on Phoronix. The Linux 3.0 power draw is up by 24% over the Linux 2.6.39 kernel. With all of these regressions, going from the Linux 2.6.38 to 3.1 kernel on an Intel Sandy Bridge notebook increases the power consumption by 76% under Ubuntu Linux and a dramatically shorter battery life.