Improving Lagging

If QubesOS is laggy, what are some steps to take to improve this? How to pinpoint the
source of lag?

You can search “laggy” in the forum and see if you have similar observation with those topics. Anyway, you need to identify ti’s the CPU or GPU that’s causing the lag.


@janglingquo_575 sorry to say that, but you make millions of single-sentence useless-for-others questions on the forum. Your questions are lacking even basic necessary details for answer. Topic titles are as bad as content, too. All that is on the edge of being called “spam”.

It makes forum less useful, less informative and polluted.
Can you, please, put a bigger effort into your posts in the future?

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Btrfs strangely gives me a more snappy experience - for now (testwise).
Have you had the same problems on R4(.1) too?
You might checkout this issue Xen-related performance problems · Issue #7404 · QubesOS/qubes-issues · GitHub

“Xephyr -no-host-grab fullscreen :o”

This is the process consuming the most CPU cycles.

Hi @janglingquo_575, it would be helpful if you could clarify what is lagging for you. Is it your network? Your web browsing? Your mouse and keyboard?

Thank you!

It is usually web browsing but, strangely, firefox does not even show up in the task manager as a process. This is both in the sys-gui VM and the non sys-gui VM.

I am unfamiliar with sys-gui myself but I was under the impression it is still an advanced configuration, and still under development. When getting started with Qubes OS, it may be best to avoid the advanced setups.

Have you reviewed the GUI domain documentation? The Xephyr process is shown and listed as an important component. If your system is struggling to run Xephyr then it may not be compatible or advisable to use a sys-gui domain at this time.

Xephyr is a nested X Window Server. But is it possible to view the processes running inside of this server?

I have a process “Xephyr -no-host-grab fullscreen :o” anybody know what is this process?

Xephyr is a nested X Window Server

Xephyr is part of the sys-gui hybrid configuration.

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the sys-gui VM needs maxed out RAM allocation. It will be sluggish otherwise, it also needs the most current and up to date fedora-xfce version to run smoothly.

Alright. Not until you mentioned sys-gui did I knew why you could see xephyr as a process. No wonder it would consume the most resources in sys-gui as it is responsible for drawing the whole screen. It’s amazing that you completed the set up of sys-gui, but as a hybrid solution, sys-gui does deprived the ability to use hardware acceleration for your DE. Normally dom0 has access to the GPU, and DEs that have complicated visual effects ( like KDE ) can use hardware acceleration. However since you are using sys-gui, all rendering are done by software. I think that’s why you’re experiencing lagging. Not much can be done from this viewpoint, unless you would like to switch to sys-gui-gpu or stop using sys-gui.

As for Firefox not showing up in taskmgr, that’s how Qubes works to protect against vulnerabilities in different software. Firefox runs inside a qube which is basically a virtual machine that is different from sys-gui. So you’ll not see a process called firefox in sys-gui’s taskmgr.

It seems that you should read the introduction at to understand Qubes better.

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I understand that Firefox and other related apps run in an isolated VM and that the process runs in the VM, not the sys-gui VM and this is the reason the process doesn’t show up.

I think you are correct about the lack of hardware acceleration here. But does the X230 Thinkpad have a GPU that can be used? Or is it an iGPU built into the CPU die itself.

This CPU has Intel HD Graphics, but how can you find which graphics drivers are being used?

I mean like OpenGL, OpenCL and DirectX X11