PowerTOP has long been available as one of the many projects out of Intel's Open-Source Technology Center that seeks to improve Linux. PowerTOP makes it relatively trivial to see your Intel system (with PowerTOP 2.1, ARM support is also being worked on). PowerTOP can be run as root and then various statistics for the CPU and GPU (as of v2.1) are displayed plus various recommendations to tweak the Linux desktop/notebook for extended battery life.
This brief PowerTOP 2.1 testing at Phoronix was done from an Intel SDV laptop bearing an Intel Core i5 2520M "Sandy Bridge" processor with HD Graphics.
Thanks to the Phoronix Test Suite with its ease-of-use for running automated benchmarks while being able to monitor the power consumption and other system vitals, a few benchmarks were carried out to see the affect of PowerTOP 2.1 when setting all of the tunables to "good" while running on battery power. With the Phoronix Test Suite it's simply a matter of setting the MONITOR=sys.power environment variable prior to running this multi-platform open-source testing framework. Alternatively, MONITOR=all can be set to monitor all of the available hardware and software sensors. Results in full for the data shared in this article are available from the 1208202-SU-INTELSAND38 result file on OpenBenchmarking.org.
When the Intel Linux notebook was idling after applying all of the PowerTOP recommendations compared to stock, the power consumption went from an average of 11.0 Watts to then idling at 9.3 Watts. So yes, PowerTOP 2.1 is still of use on modern Intel hardware running the latest Linux software.
When the GPU and/or CPU are busy though, the power-savings affect of PowerTOP is much less.
The latest release of Intel's PowerTOP open-source Linux utility can be downloaded at 01.org.