KDE's Plasma Wayland Session Achieves Better Battery Life Than With X.Org

Last week I posted some benchmarks looking at the laptop battery life implications of GNOME's Wayland vs. X.Org sessions. From that testing with a Lenovo ThinkPad T14s Gen2 with AMD Ryzen 7 PRO 5850U laptop, the GNOME Wayland session led to around 3 Watt lower power consumption than with the same software stack while logging into the X.Org-based session. For those curious about the KDE Wayland vs. X.Org power impact, here is the same set of tests carried out in the KDE space.

Due to reader interest stemming from that GNOME testing last week, off the Ryzen 7 PRO 5850U powered notebook running Ubuntu 21.10, I ran the same tests with the KDE Plasma Wayland and KDE Plasma X.Org sessions side-by-side with the GNOME results.

KDE Plasma 5.22.5 is the current desktop offered on Ubuntu 21.10.

And the same set of benchmarks via the Phoronix Test Suite were carried out:




The raw performance results weren't that different from the GNOME results, now that the KDE Wayland support especially the KWin compositor is quite mature...





Unfortunately, in some of the game tests though the performance under KDE Plasma Wayland had dipped compared to the X.Org session or the GNOME results. For those wondering about the raw gaming performance between GNOME vs. KDE currently with both X11 and (X)Wayland, I have some desktop gaming tests currently being conducted under such conditions with more interesting hardware than a laptop.

What was most interesting though for the purposes of this laptop comparison were the power results:

Like with GNOME on Wayland, the KDE Plasma Wayland results also showed a ~3 Watt battery power consumption reduction compared to the X.Org desktop session. With modern laptops, that's quite a savings.

The CPU power consumption metrics via the PowerCap interface additionally confirmed the 2~3 Watts lower with the Wayland based sessions.

This also translates to lower CPU operating temperatures over the span of all the graphics benchmarks carried out.

Looking good, Wayland.