In my recent linux adventures I explored upgrading my trusty and fully functioning Kubuntu 24.04 install (with ubuntu studio tweaks, etc) to something a bit newer, just to see if I can without issues. Answer: no I can’t.
I fresh installed both Fedora 41 KDE (kernel 6.12, plasma 6.2, wayland), and Kubuntu 24.10 (kernel 6.11, plasma 6.1, wayland).
In both distros, Ardour is so laggy that it’s basically unusable. I can’t scroll around the UI (if I scroll up and down the different UI elements update one-by-one…it takes like 2 seconds to scroll anything). Even moving the mouse over the editor is laggy (the vertical cursor line takes 1 or 2 seconds to catch up to the mouse).
In top I see XWayland consuming 100% cpu as I move or scroll around.
I tried both the latest official Ardour binary (8.10) as well as Fedora’s distro provided package with the same result.
Switching to X11 session resolves the issue.
Anybody know what’s going on?
(hardware: Asus B650E-F/7900x/4090 - nvidia drivers installed per recommendations in both distros, in Kubuntu trying the stock 560 driver and the 565 driver from PPA made no difference)
Understood. For me it doesn’t matter if it’s native wayland, or runs on xwayland, or whatever, as long as it works…
But Ardour is the only app that had the issue and it prevented me from upgrading the OS or at least using wayland (which would be helpful since I run a multi-monitor setup which is a bit clunky under X11) since one of my main workflows involves Ardour. I also tested some of my Ardour projects that use a bunch of windows plugins through yabridge (including some very graphical ones like superior drummer, fabfilter, etc), and the plugin UIs worked perfectly fine without lag in my test…only the main Ardour UI was laggy.
Not sure if this factors in but Kernel 6.12 and nVidia have been a real flakefest (on Debian anyway). Whether that spreads into Ubuntu I don’t know. Using the Window compositor as your starting point to set up a workstation seems backward to me. To me setting up a ‘mission critical’ system would rely on what is mature and established across the board not something that so far is limited to being more or less functional on the 2 most popular Desktop Environments and not necessarily running 100% smoothly on either of them yet.
Ardour and all of the Plugin frameworks are currently designed with X11 as the premise, even Studio One relies on some intermediate kludge so Plugins UI’s will work… If the DAW and Plugin frameworks are currently X11-centric Wayland is just introducing yet another variable to be negotiated at the current time anyway.
It’s also largely irrelevant to note, but I also use a multi-monitor setup (3 monitors, 2 different resolutions, one of them not always powered up) and I’ve found X/xrandr to be entirely pleasant for handling this. I do use cheapo silent radeon graphics cards, though.
I just ‘upgraded’ from an AMD 6750XT to an nVidia RTX 4080 SUPER to (a) get much faster Video upscale encoding and (b) hopefully get Davinci Resolve to finally work on my Linux partition… On Linux even with recent Kernels and the nVidia Drivers right from nVidia.com it’s completely flaky even with X11 and Davinci Resolve is sadly misnamed on Linux… maybe Davinci Devolved is more apt… maybe Davinci Explodes…
I will say on Windows 10 it’s been all I hoped and more, it absolutely flies vs. the AMD card but had I known on Linux that nVidia was so foul I never would have bought this card… Hard lesson learned; NEVER let a new application drive your hardware choices…
Seems people who upgraded kernel 6.9 → 6.10 saw the lag. The way the OP and the first person who replied describe it is spot on…XWayland thrashing a CPU, gtk apps with a lot of elements. The puzzle piece sorta fits. Unclear why I saw the issue using Fedora 41 with 6.12 though.
In the long, long distant past we used to see issues with drawing gradients on nvidia systems. I think that particular issue is long gone, but we had to put specialized code in place to help deal with that.
I made a video comparing the difference in scrolling up and down within my ardour project:
First clip is stock, on Fedora 41 wayland. I tried to scroll and it took several seconds to scroll to the bottom. I shake the mouse around as I’m waiting for the UI to update. top is showing XWayland consuming a whole CPU.
Second clip is on X11. Notice it’s immediately responsive to my scrolling.
Be assured, it’s not that we don’t believe you. It’s that we’re not going to do anything to Ardour to address whatever this is. The error is in XWayland and/or your graphics drivers.
Thanks Paul, I agree there doesn’t seem to be anything for you guys to do. I mostly just wanted to document this in case anybody sees this issue or knows a workaround, or if anybody finds out what the issue is with XWayland or for somebody to inform us that it’s fixed.
I am keeping my working system on X11 as my main driver, and have Fedora 41 on a different partition, and hoping that whatever the issue is, it gets fixed at some point.
The basic problem is that nVidia does not have a (good) open source driver, so they are always lagging in support for new kernels. You have better luck sticking with supported enterprise distributions (like Red Hat, supported Ubuntu or SuSE versions).
For years the general advice was to never buy nVidia cards if you ran linux, stick to AMD/ATI, or Intel if the Intel chipset graphics had high enough performance for what you need.
At some point nVidia got a little faster releasing their binary drivers when new kernels were released, and nouveau was good enough for a lot of use, so people started ignoring that advice. The fundamental problem remains though, nVidia does not have an open source driver so support for nVidia cards is always lagging behind the open source drivers when new kernels are released. If you are going to try to use hardware from companies that are hostile to Free Software you are just going to be stuck a little bit when using Free Software.
Lots of talk about kernel issues causing the lag, so I tried downgrading to LTS kernel 6.6 (via this copr kwizart/kernel-longterm-6.6 Copr - and also had to tell akmods to compile the nvidia driver) and it made no difference, Ardour was still laggy under XWayland. So we can eliminate that possibility.
Under Preferences → Appearance, checking the box for “Use intermediate image-surface to render canvas” and restarting…no more lag.
