Memory Usage of LXQt 0.9

Since the release of LXQt 0.9 several days ago, many people are curious about its memory usage since in the release announcement we mentioned the use of two libraries from KDE framework 5. Don’t worry! They are just “pure Qt libraries” without other KDE dependencies (Thank you KDE guys!). Good engineers always base their design desicions on careful analysis, experiments, and measurements, not politics. If a library works pretty well, it does not really matter where it comes from or it belongs to which camp. If it’s free software and it’s suitable for our need, I’d say “use it”. Here are some numbers of memory usage after cold boot.
Testing environment:

  • Debian testing (32 bit)
  • LXQt 0.9, Qt 5.3, and KF5 packages are taken from Siduction
  • Running in Virtualbox 4.3.20
  • RAM: 512 MB
  • CPU core: 1
  • Screen resolution: 1024×768
  • Measurement: Open xterm, and type `free -mh` (cache and buffer are excluded)

Memory usage after cold boot:

  • LXQt 0.9: 118 MiB
  • LXDE: 98 MiB
  • XFCE: 107 MiB
  • plain Openbox (without running any apps): 70 MiB


Well, for those who still remembered my previous report, the memory usage increased. But wait! All of the DEs, including Openbox, have the same degree of growth in memory usage. So it’s more possibly caused by the upgrade of the system itself. If you see the difference between plain openbox and LXQt, we only added 38 MiB (LXQt 0.8 added 37 MiB). Given that we migrated to Qt5 and added new features, both of which should normally increase memory usage, the current results are reasonable. Seriously, there are still room for more optimizations but we need some time to finish them.

LXQt aims to be a “modern” desktop with some “classic” designs which does not get in your way. We’re not going to clone KDE. Besides, don’t worry about resource usage. That’s the challange for developers and we’ll fight for it. 🙂