Topic by pag123123

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  • pag123123
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Topic: Pianoteq doesn't show max CPU frequency

I've installed Ubuntu Studio 20.04 on Dell Latitude E4310, Intel i5 M560 CPU.

I've edited /etc/security/limits.conf to request real-time scheduling.

In Ubuntu Studio Controls, it says "Real Time Permissions Enabled" (although there is light grey background, so I'm not sure if it's greyed out?)

I can set 'CPU Governor' to 'performance', with 'Intel boost' off, and exit. However, reopening Studio Controls shows 'ondemand'.

In Pianoteq 6.2.7, CPU freq is not max of 2.67GHz.

I've tried cpufreq-set for each CPU core, but I get this:

sudo cpufreq-set -c 0 -g performance
[sudo] password for phil:
Error setting new values.
Common errors:
- Do you have proper administration rights? (super-user?)
- Is the governor you requested available and modprobed?
- Trying to set an invalid policy?
- Trying to set a specific frequency, but userspace governor is not available, for example because of hardware which cannot be set to a specific frequency or because the userspace governor isn't loaded?

Puzzled newbie here...!

Reply by sjgcit

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  • Registered: 26-04-2016
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Re: Pianoteq doesn't show max CPU frequency

I use Linux Mint 18 (based on Ubuntu Xenial 16.04) at the moment on a (relatively) old Xeon E3-1240 cpu and I found the best way to get CPU "performance" set was to install a desktop widget called "indicator-cpufreq" from the Synaptic tool.

I have it set as one of the "Startup Applications".  It will default to "Powersave" mode but I can just click the desktop widget and pick "Performance" anytime.

In practice I've found Pianoteq 6.7 does quite well without having performance set, but there seems to be an increased likelihood of crackling which seems to be the CPU prematurely dropping frequency too easily on Powersave.  Unfortunately Powersave is the default mode set by the kernel.  I have not found a way to force this to remain at Performance myself.  Inveryday use I have found using the desktop widget simple and effective.

Make sure your user has the "rtkit" group permission as that is the realtime group and you may not have user control of the realtime aspects of the system configuration without that.

StephenG

Reply by sjgcit

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Re: Pianoteq doesn't show max CPU frequency

I found an interesting post and answers on AskUbuntu.com : https://askubuntu.com/questions/1021748...e-in-18-04

Once answer does indicate that the system drops to Powersave mode even if Performance (or something else) is set as a result of a specific action in the system startup scripts.  I would describe that as a bug, but in any case it may happen in your case too.

Note that your CPU probably only supports the "powersave" and "performance" governors, and if you read references to other governors they relate to later CPU models these were introduced on.

StephenG