Author Topic: excessive CPU useage  (Read 795 times)

m7b52000

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excessive CPU useage
« on: April 27, 2022, 06:38:47 AM »
Apart from some minor soldering issues the kit and software are working. The CPU usage however swings between 55% and 100% every few seconds with only 2 effects added to a pedalboard, even when they are turned off and there is no signal being processed. Is there a setting I need to check or modify?

cheers

Randall (Admin)

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Re: excessive CPU useage
« Reply #1 on: April 27, 2022, 04:56:56 PM »
Although that can happen with some larger pedalboards with 8+ effects, you generally shouldn't be seeing that for 2 effects.  Which effects?  Does it do that for all the starter pedalboards too?

One easy thing you can do is switch to 256 Frames in the MOD UI.  Bottom of the UI, just click "128 Frames" and it'll toggle to 256.  It should use a lot less CPU then.  Your latency will increase from about 5ms to 10ms but most people don't notice.

You can make that the default (so you don't have to change it in the UI every time), by editing /etc/jackdrc and changing "-p 128" to "-p 256".  Then reboot.

m7b52000

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Re: excessive CPU useage
« Reply #2 on: April 28, 2022, 12:21:19 AM »
Randall,

Thanks, changing to 256 frames has made all the difference and the latency is not an issue.

Do I need admin permissions to modify /etc/jackdrc?. I tried to backup jackdrc to jackdrc_bkp to be safe but was told: "cp: cannot create regular file 'jackdrc_bkp': Permission denied'. I have played with linux in the past and this looks like a permission issue? If I save a pedalboard with the 256 setting will that be saved to the Pi-stomp for that pedalboard, permanently?

cheers,

Tony

Randall (Admin)

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Re: excessive CPU useage
« Reply #3 on: April 28, 2022, 12:28:21 AM »
Glad that saved ya.  You do need root permissions to edit that so put "sudo" in front of whatever edit command:

sudo vi /etc/jackdrc
OR
sudo nano /etc/jackdrc

The frames (buffer) setting is Not stored for the pedalboard, it is a setting of jack (the audio host).

You can also edit jack settings by using the patchbox utility (just the command: patchbox)



m7b52000

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Re: excessive CPU useage
« Reply #4 on: April 28, 2022, 12:32:50 AM »
Thanks,

I thought I would never have to use vi ever again....

Tony