Hello, we are using the Verdin iMX8M Mini with a custom carrier board and our own distro. The CoM should require as little and constant power consumption as possible. Is it possible to define a lower CPU frequency via the opp table in device tree?
Hello @philipp1,
We would recommend that you avoid doing such changes if possible, trying first to change the scaling governor for the CPU or disabling cores if needed.
Please read more about this here: How to Lower CPU Power Consumption | Toradex Developer Center
That being said, it should be possible to change the CPU frequency of the A53 cores by changing the operating table in the device tree.
Please note that operating the CPUs outside of supported conditions is not recommended and may cause stability issues and failure of the SoC.
Best Regards,
Bruno
Hello @bruno.tx
thank you for your reply. I have already been able to save a lot by using the scaling governor and switching off all unecessary CPUs.The lowest clock frequency from 1.2GHz is more than sufficient for our purposes and could be reduced. Do you already have experience with lower clock frequencies?
We run at 1Ghz with no problems.
I think I remember NXP saying that there is, in practical terms, no theoretical minimum frequency for the A53 CPU, but I can’t find the reference now and we had no need to go lower than 1GHz
Andy
Hello @philipp1,
As far as I am aware, we have not tested the Verdin iMX8M Mini at lower clock frequencies than the one the CPU was validated at.
Depending on the CPU governor you have configured, you may already be at 1.2 GHz at most if not all times.
You can check the time spent in each state in /sys/devices/system/cpu/cpu0/cpufreq/stats.
The following example is from a system using the default ondemand CPU governor:
root@verdin-imx8mm-06898561:~# cat /sys/devices/system/cpu/cpu0/cpufreq/stats/time_in_state
1200000 57327
1600000 946
Best Regards,
Bruno
I found this:
Regards,
Andy
1 Like