Using PowerTOP 2.6 Saves Power, Extends Battery Life On Ubuntu 14.04
The Apache compile-time performance was unchanged by PowerTOP but it was running a bit slower with Linux 3.15.
When running the compile task on GCC, the average power use on the clean Ubuntu 14.04 install for the ASUS ultrabook was 24.5 Watts but it dropped to 21.9 Watts when tweaking all of the PowerTOP tunables to their good values; there were similar power benefits with the Linux 3.15 kernel.
The C-Ray multi-threaded ray-tracer led the system to burn through 24 Watts while running this heavy CPU benchmark but with the PowerTOP optimizations the average power draw was just 22 Watts.