(Solved!) Windows Audio vs. Linux Audio

[TAERSH]

For shits & giggles I'll sometime run it at 32 frames, and might just see a single Xrun

On my Linux machine I got the first Xrun already after Qtractor completely started with a template loaded. Perhaps it's caused by the templates I'm using. They are huge. They usually at least have 120 tracks pre-setup to make me able to start composing/recording with all my favorite sounds immediately available and usable.

At times when I was using stand alone synthesizers instead of the plugin versions, I didn't have Xruns after Qtractor was ready with those templates used. So, definitely there's a difference between the use of stand alone and plugin versions of synthesizers.

[TAERSH]

Xruns are your master.

That's a very stupid statement and of course simply not true.

On my soundcloud account everything -by the exception of one or two songs- was composed, recorded, arranged and mixed down with different versions of my GNU/Linux Operating Systems.

In December 2019 alone I composed, recorded, arranged and mixed around 16/17 songs within around 11/12 days with my GNU/Linux OS.
In 2020 I composed, recorded, arranged and mixed 2 hours and 26 minutes of music with my GNU/Linux OS.
In 2021, until today I composed, recorded, arranged and mixed 2 hours and 2 minutes of music with my GNU/Linux OS.

If Xruns would be my master, I never would have done all these songs by the use of GNU/Linux.

[Loki Harfagr]

Ouch!
16/17 and 11/12 are very difficult times!

[TAERSH]

Ouch!
16/17 and 11/12 are very difficult times!

Sorry for being misunderstood.

I meant 16 or 17 songs in 11 or 12 days. I can't recall this exactly as some of my December 2019 songs having a real title. Those other songs are titled after the date and time of starting to compose.

And just to make sure: there are no times like xx/17 or xx/12 or even xx/15 etc.
There's only such like x/4, x/8, x/16 - perhaps there's also xx/32 but I never heard of this.
These times are created by division and marked via bars on the scores neck/up-bars (1, 2, 3, 4 bars horizontal)
Yes, on can have quintuplets which would be equal to x/5 but that's not able to write down using general types of musical scores.
There's some symbols to be used to mark a group of scores as quintuplets etc.pp.

[TAERSH]

Cut for restart of Topic!

[TAERSH]

Damn!

The last time I checked my real time configuration was around the end of 2019. At these days I was still using the stand alone versions of software synthesizers. I wasn't familiar with the use of their plugin versions or mainly thought, plugins are only for stuff like Equalizers, Compressors, Reverbs and stuff.

Since the last time I checked my real time configuration I switched the kernel used two times without checking again.
Started from 5.0.21-rt15 which was the real time kernel taken from the latest Puppy Studio aka Studio 1337 by Iowt3ch.
I switched to 5.4.5-rt3 and then to 5.11.4-rt11 which were created by another guy.

Right now, a few minutes ago (I changed some stuff in my OS and rebuilt it) I checked real time configuration again.
It returned, Kernel with real time preempt NOT FOUND!

Both of those kernels I used at last have been announced and published as being real time kernels.

I switched back to the kernel 5.0.21-rt15, rebooted and checked real time configuration again.
It returned, Kernel with real time preempt FOUND!

So, now I'm looking forward to the upcoming results of Xruns within my next compositions.

My conclusion of this: never ever trust any Guys -no matter if Linux or Windows- without checking the facts by yourself.

[TAERSH]

Contacted the Guy who created those kernels.
He said, they are compiled with preempt and real time enabled.
His benchmarks showing both of them running with preempt and in real time.

Maybe there's something wrong with the real time configuration quickscan tools?

However, I made some testings by the use of an older composition which uses a lot of tracks, synthesizers and different other plugins.
Can't notice any difference between all five different real time kernels I have available locally.

PREEMPT found
4.19.15-rt12
4.19.82-rt30
5.0.21-rt15

PREEMPT not found
5.4.5-rt3
5.11.4-rt11

Maybe I got a wrong CPU?
It's an AMD Ryzen 5 2600X Six-Core CPU.
Realtime config quickscan complains also about missing directories for the CPU governor which should be set to PERFORMANCE.
E.g.: /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor FILE/DIR NOT FOUND

Instead I set CPU to full performance/power within the BIOS and disabled all the running in QUIET mode stuff.
So, they all are running usually at around 3096 Mhz constantly.

[Toejam76]

Maybe I got a wrong CPU?
It's an AMD Ryzen 5 2600X Six-Core CPU.

The CPU should be fine. When I do "uname -a" it says on a Ryzen 3400g with the kernel from UbuntuStudio:

Linux plasmabox 5.11.0-31-lowlatency #33-Ubuntu SMP PREEMPT Wed Aug 11 14:21:21 UTC 2021 x86_64 x86_64 x86_64 GNU/Linux

"inxi -C" however does not list that feature. It's probably working, but not recognized by the script I would assume.
One thing about the Ryzen CPUs is that the BIOS/AGESA has to be up to date. There were quite a few changes affecting stability and performance.
Btw, I also made some changes in the BIOS to disable everything not needed to free IRQs, especially the NIC which I don't use, but Linux seems to ignore that. I don't have underruns at all if the interface (Scarlett Solo) is alone on a USB 2 hub, but on any other I get distortion and underruns. Ubuntu Studio and maybe Linux lowlatency in general seems very strict about it's reserved IRQs. It also doesn't like wifi scanning or active network in general when running low latency audio.
It's not everyone's cup of tea, but my go-to is a Ubuntu-based distro with the UbuntuStudio Installer. That seems to work pretty good at least in my case and I don't change anything anymore, because like a wise man once said "never change a running system".

[TAERSH]

Code: Select all

root# uname -a
Linux puppypc1448 5.11.4-rt11 #1 SMP PREEMPT Sat Mar 13 18:36:56 EST 2021 x86_64 x86_64 x86_64 GNU/Linux
root#

Hmm, it says PREEMPT, so there must be something wrong with realtime config quickscan tools...

[Loki Harfagr]

Which "realtimeconfigquickscan" stuff and version did you use?
The supposed last best bet should be that "r40.e50825d" here:
https://github.com/raboof/realtimeconfigquickscan

[TAERSH]

@Loki Harfagr
Don't know the version. Downloaded some times in the beginning of 2020.
Right now I downloaded the latest version of realtime config quickscan and made a scan. It seems to be alright now.

Code: Select all

== GUI-enabled checks ==
Checking if you are root... yes - not good
You are running this script as root. Please run it as a regular user for the most reliable results.
Checking filesystem 'noatime' parameter... 5.11.4 kernel - good
(relatime is default since 2.6.30)
cat: /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor: Datei oder Verzeichnis nicht gefunden
cat: /sys/devices/system/cpu/cpu1/cpufreq/scaling_governor: Datei oder Verzeichnis nicht gefunden
cat: /sys/devices/system/cpu/cpu10/cpufreq/scaling_governor: Datei oder Verzeichnis nicht gefunden
cat: /sys/devices/system/cpu/cpu11/cpufreq/scaling_governor: Datei oder Verzeichnis nicht gefunden
cat: /sys/devices/system/cpu/cpu2/cpufreq/scaling_governor: Datei oder Verzeichnis nicht gefunden
cat: /sys/devices/system/cpu/cpu3/cpufreq/scaling_governor: Datei oder Verzeichnis nicht gefunden
cat: /sys/devices/system/cpu/cpu4/cpufreq/scaling_governor: Datei oder Verzeichnis nicht gefunden
cat: /sys/devices/system/cpu/cpu5/cpufreq/scaling_governor: Datei oder Verzeichnis nicht gefunden
cat: /sys/devices/system/cpu/cpu6/cpufreq/scaling_governor: Datei oder Verzeichnis nicht gefunden
cat: /sys/devices/system/cpu/cpu7/cpufreq/scaling_governor: Datei oder Verzeichnis nicht gefunden
cat: /sys/devices/system/cpu/cpu8/cpufreq/scaling_governor: Datei oder Verzeichnis nicht gefunden
cat: /sys/devices/system/cpu/cpu9/cpufreq/scaling_governor: Datei oder Verzeichnis nicht gefunden
Checking CPU Governors... CPU 0: '' CPU 1: '' CPU 10: '' CPU 11: '' CPU 2: '' CPU 3: '' CPU 4: '' CPU 5: '' CPU 6: '' CPU 7: '' CPU 8: '' CPU 9: ''  - not good
Set CPU Governors to 'performance' with 'cpupower frequency-set -g performance' or 'cpufreq-set -c <cpunr> -g performance' (Debian/Ubuntu)
See also: http://linuxmusicians.com/viewtopic.php?f=27&t=844
Checking swappiness... 10 - good
Checking for resource-intensive background processes... none found - good
Checking checking sysctl inotify max_user_watches... >= 524288 - good
Checking whether you're in the 'audio' group... yes - good
Checking for multiple 'audio' groups... no - good
Checking the ability to prioritize processes with chrt... yes - good
Checking kernel support for high resolution timers... found - good
Kernel with Real-Time Preemption... 'threadirqs' kernel parameter - good
Checking if kernel system timer is high-resolution... found - good
Checking kernel support for tickless timer... found - good
== Other checks ==
Checking filesystem types... ok.
** Set $SOUND_CARD_IRQ to the IRQ of your soundcard to enable more checks.
   Find your sound card's IRQ by looking at '/proc/interrupts' and lspci.

[TAERSH]

Ok, I got another Kernel now. It's the 5.4.70-rt40

Output of realtime config quickscan (latest version) for 5.4.70-rt40:

Code: Select all

== GUI-enabled checks ==
Checking if you are root... yes - not good
You are running this script as root. Please run it as a regular user for the most reliable results.
Checking filesystem 'noatime' parameter... 5.4.70 kernel - good
(relatime is default since 2.6.30)
cat: /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor: Datei oder Verzeichnis nicht gefunden
...
Checking CPU Governors... CPU 0: '' CPU 1: '' CPU 10: '' CPU 11: '' CPU 2: '' CPU 3: '' CPU 4: '' CPU 5: '' CPU 6: '' CPU 7: '' CPU 8: '' CPU 9: ''  - not good
Set CPU Governors to 'performance' with 'cpupower frequency-set -g performance' or 'cpufreq-set -c <cpunr> -g performance' (Debian/Ubuntu)
See also: http://linuxmusicians.com/viewtopic.php?f=27&t=844
Checking swappiness... 10 - good
Checking for resource-intensive background processes... none found - good
Checking checking sysctl inotify max_user_watches... >= 524288 - good
Checking whether you're in the 'audio' group... yes - good
Checking for multiple 'audio' groups... no - good
Checking the ability to prioritize processes with chrt... yes - good
Checking kernel support for high resolution timers... found - good
Kernel with Real-Time Preemption... found - good
Checking if kernel system timer is high-resolution... found - good
Checking kernel support for tickless timer... found - good
== Other checks ==
Checking filesystem types... ok.
** Set $SOUND_CARD_IRQ to the IRQ of your soundcard to enable more checks.
   Find your sound card's IRQ by looking at '/proc/interrupts' and lspci.

Grep output of /boot/config- for 5.4.70-rt40:

Code: Select all

root# grep -e "CONFIG_IRQ_FORCED_THREADING=y" -e "CONFIG_PREEMPT_RT=y" /boot/config-`uname -r`
CONFIG_IRQ_FORCED_THREADING=y
CONFIG_PREEMPT_RT=y
root#

This seems to be good, so far.
The complain about CPU Governors should not affect anything (hopefully), since I disabled all the Run in quiet mode stuff in main board's BIOS.
So, all 12 CPU threads running almost between 3000 and 4000 Mhz.

[TAERSH]

After some days working with Kernel 5.4.70-rt40 almost all Xruns seems to be gone.
Only 1 Xrun after loading the project.
A few more when loading a project using Windows VST plugins.
No Xruns at work etc.

Screenshot.jpg (20.21 KiB) Viewed 10437 times

[TAERSH]

Hi.

After refining some of my settings for real time audio configuration I don't have any Xruns anymore.
Zero Xruns after loading a project and working on it (no Windows VST plugins used).
And also zero Xruns after loading a project and working on it (with Windows VST plugins used).

See Screenshots:

Screenshot.jpg (162.05 KiB) Viewed 10376 times

Screenshot(1).jpg (25.72 KiB) Viewed 10376 times