There are dropouts, clicks and pops on my system when I interact with UI.
First I thought that it mainly happens with plugin GUIs that rely on openGL, such as LSP GOTT or Usual Suspects JE-8086, but I also get clicks when I switch the window.
I used the ubuntu-studio configurator, so I assume all settings are optimized.
Some system (hopefully helpful) information. user@user-ThinkPad-P1:~$ uname -a Linux user-ThinkPad-P1 6.17.0-6-generic #6-Ubuntu SMP PREEMPT_DYNAMIC Tue Oct 7 13:34:17 UTC 2025 x86_64 GNU/Linux
user@user-ThinkPad-P1:~$ pipewire --version pipewire Compiled with libpipewire 1.4.7 Linked with libpipewire 1.4.7
Hardware is old (2019) but beefy:
Lenovo ThinkPad P1
16.0 GiB RAM
Intel® Core™ i7-8850H × 12
Intel® UHD Graphics 630 (CFL GT2)
Nvidia Quadro P2000 with Max-Q Design
1.0 TB SSD
Unsuccessful Troubleshooting attempts so far:
Try different audio interfaces (built in, zoom H4n via USB)
Try different Buffersizes and sampling rates.
try the above, but with jack instead of pipewire.
Run ardour with Nvidia GPU (listed in nvidia-smi)
disable nvidia GPU and run everything on the internal.
blacklist snd_hda_intel in /etc/modprobe.d
try all this on wayland(gnome) and all this on xorg (xfce)
try with or without raysession.
What else can I try? Any help, ideas, rituals or prayers would be highly appreciated.
if you still have problems, go into the bios and temporarily disable the external graphics card. load ardour and see if there is a difference. i am not sure on that particular model of thinkpad but the older thinkpads with external graphics cards were very clunky on drivers with issues of gpu switching and just management of graphics. i had more than a few thinkpads on linux and one old thinkpad laptop glitches constantly due to the gpu. so i disabled gpu via bios , and the problem was fixed on ubuntu. keep in mind that some external gpus on some linux thinkpad laptops only had good control of gpu settings via windoze. total pain in the … but important to know these computers.
weirdly enough, i went from ubuntu to linux mint similar version and display server on that same laptop without disabling and had no issues; though i did not put it through full ardour testing. did not have time to check into it further cause moved on to new computer but hopefully that gives you some additional light and prevents you from going to years of therapy to overcome these hardships with older thinkpad external gpus.
I guess this means that the rtirq is correctly applied by the Ubuntu Studio Audio Configuration tool. Do I need to set anything else?
For example what about RTIRQ_HIGH_LIST in /etc/default/rtirq? Does it make sense to add ardour, ray session etc to that list?
Thanks @kenzel, I already switched between internal and discrete GPU using prime-select (everytime rebooting in between testruns).
I tried to follow your advice to lock to a GPU on the BIOS level, but there I can only choose between Hybrid or the discrete NVIDIA device. I tried the discrete option, to prevent any switching. nvidia-smi command confirmed that everything is running on the discrete GPU.
Unfortunately, no success. It even got worse, I assume because spreading the load across GPUs does help at least a little bit. In hybrid mode with prime-select on-demand, the desktop on my system was automatically drawn using the NVIDIA gpu.
Again, thanks for your input. If you have any other ideas, I am all ears. Also, it might be nice to get the number of your therapist.
No, rtirq is a system script that is not related to the kernel options (other than threadirqs needs to be available).
The rtirq script has a configuration file where you set the priority order for the devices you want to have RT priority, and all the non RT devices get set to the same lower priority.