Googling for various requests on topic gave me no clue if I'm doing everything right, so, please, help me understanding my current state
Current state
For now I have fully working Ubuntu Studio 20 (please check full hardware info in my signature)
I've accomplished full automation of startup, my goal was to start a station by powering it on and be able to play live in 2-5 minutes with no access to the keyboard, mouse and monitor. So now I can.
A Question
Can I improve my station further?
For example, I am running my USB audio interface (Scarlett 2i2) with buffer size of 128. I want to decrease that value to minimise the latency but I am afraid that will increase XRuns. Carla says I have 13% of DSP load in idle state.
I am not sure I am using my Scarlett 2i2 at its full potential.
I mean, I did nothing with it, I just plugged it in. Maybe I should do some adjustments?
JACK
In my qJackCtl on Settings tab there's ALSA selected with Interface set as (default), Sample rate set as 44100, Frames/Period is 1024 and Periods/Buffer is 3. Carla shows it as system device. Also, latency is 69.7 ms. I can live this way but I will be happy to make it smaller and increase overall stability.
Steps I've done so far
1) I followed this guide. Some adjustments were in place as Ubuntu Studio already does a lot of stuff. My first attempt was a LUbuntu with lowlatency kernel - and it was hell. Distros are better when you're noob.
2) I learned about IRQs and disabled all unnecessary hardware from BIOS including internal audio interface (HDAudio), internal LAN interface (I am using WAN card so I don't need both), HPET was been turned off - so I enabled it.
3) noatime was a miracle fix. My system speeded up drastically.
4) I can't mess with CPU Governor. I don't know why. If I change it from Ubuntu Studio 20 GUI it resets to 'on demand' when I reopen the settings window. Also, realTimeConfigQuickScan suggests things I can't do - neither cpupower nor cpufreq-set are persist in my system.
Atom 330 supports no speedstep and always runs at its maximum, I believe
Additional info
Here's full output of that script:
Code: Select all
== GUI-enabled checks ==
Checking if you are root... no - good
Checking filesystem 'noatime' parameter... 5.4.0 kernel - good
(relatime is default since 2.6.30)
cat: /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor: No such file or directory
cat: /sys/devices/system/cpu/cpu1/cpufreq/scaling_governor: No such file or directory
cat: /sys/devices/system/cpu/cpu2/cpufreq/scaling_governor: No such file or directory
cat: /sys/devices/system/cpu/cpu3/cpufreq/scaling_governor: No such file or directory
Checking CPU Governors... CPU 0: '' CPU 1: '' CPU 2: '' CPU 3: '' - 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 - not good
increase max_user_watches by adding 'fs.inotify.max_user_watches = 524288' to /etc/sysctl.conf and rebooting
For more information, see http://wiki.linuxaudio.org/wiki/system_configuration#sysctlconf
Checking access to the high precision event timer... readable - good
Checking access to the real-time clock... readable - 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... not found - not good
Kernel without 'threadirqs' parameter or real-time capabilities found
For more information, see https://wiki.linuxaudio.org/wiki/system_configuration#do_i_really_need_a_real-time_kernel
Checking if kernel system timer is high-resolution... found - good
Checking kernel support for tickless timer... found - good
== Other checks ==
Checking filesystem types... ok.
Checking for devices at IRQ 18... did not find multiple. ok.
