How useful is TLP for Ubuntu 18.04 and 18.10?


#1

One of the improvement of Ubuntu 18.10 was supposedly a better battery usage. So is supposed the use of TLP but I was never able to see the difference with or without it. Therefore I decided to experiment a little.
I used Ubuntu 18.04 (Bionic Beaver) on a Thinkpad X220 with a small, but recent, battery. In order to have the same kind of discharge my test sequence was to start the stopwatch at boot up and watch video full screen with VLC until the alarm of 5% charge remaining sounded. I used tlpui GUI to tun on or off TLP. Then I upgraded the laptop to Ubuntu 18.10 (Cosmic Cuttlefish) and repeated the test.
Result are as follows:
Ubuntu 18.04 with TLP off: 103 mn
Ubuntu 18.04 with TLP On: 115 mn (+11.6% compared to 18.04 with TLP off)
Ubuntu 18.10 with TLP off: 114 mn (about the same as 18.04 with TLP On)
Ubuntu 18.10 with TLP On: 123 mn (+ 7.9% compared 18.10 with TLP off)
My conclusion is that it seems that TLP has always a positive effect on battery usage time. No so marked for Ubuntu 18.10 but every little bit helps!
Also the claim that Ubuntu 18.10 better manages battery usage seems indeed to be verified.
I like the look and feels of Cosmic Cuttlefish so I will keep it and let TLP run by default.
Do you have the same experience or is there a more scientific test anywhere supporting my qualitative findings?


#2

It very much depends on the hardware and not only how old or used up it is. There are so many variables to consider that it’s basically impossible to do a general test that applies to most computers/laptops. E.g. if your laptop has a gaming graphics card but you only browse and read text documents then it might draw more power than an Intel HD iGPU. But if you have the same graphics card, play only games the whole time and compare the power draw to an Intel HD playing the same game then obviously the gamer graphics card will win, because it is suited for such usage and copes better with the target usage.
Also your test was just running a Video. So you mainly tested the power draw of your graphical processing unit. If you want a good test, there should be like 20 different laptops of all styles and qualities tested one time with a CPU stress test on and the second time with a GPU stress test on. Then the results would maybe be a bit more referrable.


#3

Completely agree with all you said. I forgot to tell that the hard disk is SSD, would it be different with a HDD?
I don’t have the patience to do word processing for 2 h and I do not do games so, if someone else has been able to make a comparison with/without TLP in a different context that would confirm (or not) my initial impression that TLP indeed bring some sizable improvement. Thanks for the feedback


#4

Very interesting results. I have had similar results, with tlp always producing about 7 % better battery life than without it. I have noticed this on Mint and Kubuntu.
One of the things I think that holds linux back is laptop battery usage. and there should be more development in this area. Thanks for taking the time to do the tests.