F19 Power Management Test Day Early Report

Thanks all who attended the event (personally or online). There were about 40 visitors during the day in our "test room" in Brno office and it was really great to meet there. The demand was more than the available room could handle :) and we are sorry for the limited number of seats. Most of the visitors helped us with the testing and went through the prepared test cases. As a thank you they got a small gift from us.

On the attached picture you can see testers in action :). Notice the graph on the TV in the background - everybody who connected her/his machine to our measurement equipment was able to see it's power consumption in the real time on that TV.

As the proof that Fedora is ARM friendly, we had there Cubieboard, of course running Fedora 19 :) Later in the day we used it for the real time power consumption graphing, replacing the dedicated PC and saving a lot of energy :).

Few visitors were interested in Fedora 19 in general. That wasn't problem, because we had there spare laptops with Fedora 19 pre-release installation, so they could freely try it and ask questions. We also ran the test day online and provided guidance on the #fedora-test-day Freenode IRC channel. We did our best, but sometimes it was really hard to handle it all, so we are very sorry if you experienced increased latency in our IRC responses.

So far many of the testers have already submitted their results. Such feedback is very valuable for us. If you missed the event, you can still participate online, just follow the instructions on the test day wiki http://fedoraproject.org/wiki/Test_Day:2013-04-17_Power_Management. And of course don't forget to submit your results :). We plan to release the detailed stats later (it will be calculated from the data submitted till 2013-04-28).

F19 Power Management Test Day

Fedora 19 power management test day will start this Wednesday (2013-04-17). The event will be mainly focused on laptops, but even desktop machines can be tested. There are also prepared three test cases which are suitable for secondary architectures, thus e.g. if you are running Fedora 19 pre-release on your ARM box, please join us and share your numbers. There are also prepared special test cases targeting aggressive power-savings on Intel, Nvidia and ATI / AMD (Radeon) graphics cards. This is also on-site event that is running along with the Redhat Open House event. So if you are near Brno, feel free to join us in person. You can bring your hardware and test it there. There will be available calibrated digital power meter (Chroma 66202) so you will be able to measure power consumption of your hardware. Live USB/CD will be available so you can participate in the test day and not affecting your production machine. There is also prepared new web application which you can use for submitting your results, but if you prefer the wiki, you can still submit your results through the wiki as usual. Everybody is welcome to attend this event and your attendance will help us to make the Fedora better. Going through all test cases take less an hour, but you don't need to finish them all - just select test cases you are interested in, partial results are also valuable for us. Just visit the PM test day WWW page http://fedoraproject.org/wiki/Test_Day:2013-04-17_Power_Management and follow on-site instructions or join us in person.

F17/F18 simple power consumption comparison on Lenovo T520

Fedora 18 is out and I had spare Lenovo ThinkPad T520 so I performed a simple check how it stays against Fedora 17 regarding power consumption. The check was very simple, only 4 tests were run on default installation of Fedora 17/18:

1. Active idle test - crond disabled and 30 min in the idle for stabilization then for 3 x 20 min the energy consumption was measured. From these 3 results the average power consumption was calculated.
2. Archive (tar.bz2) unpack - the test archive was unpack 3 times on ext4 root partition. Between each run the VM cache was dropped. Energy consumption was measured and average power consumption was calculated.
3. Kernel rebuild - kernel-3.7.4-104 srpm was rebuild in mock (one time only). Energy consumption was measured and average power consumption was calculated. In the measurement the mock setup and builddeps installation wasn't counted.
4. PowerTOP statistics (number of wakeups) - PowerTOP tool was run for 3 x 20 seconds and average number of wakeups was calculated.

For the measurement the Chroma 66202 Energy Star measurements compliant wattmeter was used. The energy consumed from the AC outlet was measured. It means that losses on the cabling and AC/DC adapter are counted in the results, so if you run on the battery the real power consumption will be slightly lower. The Lenovo ThinkPad T520 was used for the test. It has Intel Core i7-2640M CPU @ 2.80GHz and 8GB RAM. LCD backlight and wireless was turned off during the test.

Table 1: Results

Test	Fedora 17	Fedora 18
Active idle Pavg [W]	10.221	8.748
Archive unpack Pavg [W]	31.346	31.341
Kernel rebuild Pavg [W]	34.907	34.588
Wakeups count [1]	39.3	56.7

From the table 1 it is apparent that the power consumption under the load is nearly the same (probably the same due to measurement error). For the active idle the power consumption of Fedora 18 was lower. Unfortunately I haven't time to observe the reason of this, but I am going to do more tests on different HW to proof that it wasn't some anomaly. The wakeups count are comparable. Different PowerTOP versions was used for the measurement and it may be the source of the small difference. The good message is that there wasn't observed any regression in Fedora 18 regarding power consumption (on T520).