Looking At The Power Use From Linux 4.6 To Linux 4.15

In addition to looking at system boot times from Linux 4.6 to Linux 4.15, while doing this kernel testing session on the Lenovo ThinkPad I also took some battery power consumption measurements.

Using the Lenovo ThinkPad X1 Carbon with Core i7 (Broadwell) processor, I also compared the battery power consumption on these tested mainline Linux kernels from 4.6 to 4.15.

The Phoronix Test Suite was automatically polling the battery power consumption while the Ubuntu 17.10 laptop each time was idling at the GNOME Shell (Wayland) desktop.

The average power consumption of this Broadwell laptop basically was the same from Linux 4.6 through 4.15. Unfortunately I wasn't able to go back further as 4.5 and earlier weren't booting with the 17.10 user-space.

So no real surprises from these numbers, but the kernel's impact on power use is highly dependent upon the particular hardware at play. As such, I'll be doing similar tests on a more diverse range of hardware in the near future. Benefiting some laptop users with Linux 4.15 will be this SATA link power management improvement, among other improvements now being tackled by Red Hat.