Table of Contents
How to set max cpu frequency and cores
- Ubuntu : Available with 3.14.77-80 (Sep 8, 2016) or higher version
- Android : Available with Android v2.2 or higher version
For further information, you can refer to the following forum thread.
How to set max cpu frequency
Here are the available cpu frequency sets and you can set one of them as max. cpu frequency using boot.ini
The available list of cpu frequency set
Here are the common sets we recommend under normal conditions.
| frequency | notation on boot.ini |
| 1.656 GHz | “1656” |
| 1.536 GHz | “1536” |
| 1.296 GHz | “1296” |
| 1 GHz | “1000” |
| 500 MHz | “500” |
| 250 MHz | “250” |
| 100 MHz | “100” |
There are some advanced frequency sets you can try below.
The following sets are unstable with 2 or more cpu-cores so, you should adjust cpu cores as described the next section.
| frequency | notation on boot.ini | note |
| 1.680 GHz | “1680” | booting OK with 4 cores / recommend 3 cores for heavy load test |
| 1.752 GHz | “1752” | booting OK with 4 cores / recommend 2 cores for heavy load test |
| 1.896 GHz | “1896” | booting OK with 1~3 cores / recommend running with a single core |
| 1.920 GHz | “1920” | booting OK with 1 or 2 cores / recommend running with a single core |
| 1.944 GHz | “1944” | booting OK with a single core but unstable |
| 2.016 GHz | “2016” | extremely unstable |
setting boot.ini
Please modify max_freq based on the aforementioned frequency table. The unit of max_freq in boot.ini is MHz.
If you don't set max_freq in bootargs or the setting value is wrong one which doesn't exist in frequency table, max_freq will be set as “1.536GHz” by default.
### boot.ini
# max cpu frequency in dvfs table / in MHz unit
# setenv max_freq "2016" # 2.016GHz
# setenv max_freq "1944" # 1.944GHz
# setenv max_freq "1920" # 1.920GHz
# setenv max_freq "1896" # 1.896GHz
# setenv max_freq "1752" # 1.752GHz
# setenv max_freq "1680" # 1.680GHz
# setenv max_freq "1656" # 1.656GHz
setenv max_freq "1536" # 1.536GHz
# Boot Arguments
# add max_freq in bootargs
setenv bootargs "root=UUID=e139ce78-9841-40fe-8823-96a304a09859 rootwait ro ${condev} no_console_suspend max_freq=${max_freq} hdmimode=${m} ${comde} m_bpp=${m_bpp} vout=${vout} fsck.repair=yes net.ifnames=0 elevator=noop disablehpd=${hpd}"
After setting it, then be sure you do reboot.
You can check the frequency list as following.
ex) setenv max_freq “1656”
root@odroid64:~# cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies 100000 250000 500000 1000000 1296000 1536000 1656000
How to set the number of cpu cores
Also, you can set cpu-cores you want to activate using boot.ini
The available range is “1” to “4”
setting boot.ini
### boot.ini
# max cpu-cores
# setenv maxcpus "1"
# setenv maxcpus "2"
# setenv maxcpus "3"
setenv maxcpus "4"
# Boot Arguments
# add max_freq in bootargs
setenv bootargs "root=UUID=e139ce78-9841-40fe-8823-96a304a09859 rootwait ro ${condev} no_console_suspend max_freq=${max_freq} maxcpus=${maxcpus} hdmimode=${m} ${comde} m_bpp=${m_bpp} vout=${vout} fsck.repair=yes net.ifnames=0 elevator=noop disablehpd=${hpd}"
After setting it, then please be sure you do reboot.
You can check the activated cpu cores as following.
ex) setenv maxcpus “2”
root@odroid64:~# cat /sys/devices/system/cpu/online 0-1 root@odroid64:~# cat /sys/devices/system/cpu/offline 2-3
root@odroid64:~# cat /proc/cpuinfo processor : 0 BogoMIPS : 2.00 Features : fp asimd crc32 CPU implementer : 0x41 CPU architecture: 8 CPU variant : 0x0 CPU part : 0xd03 CPU revision : 4 processor : 1 BogoMIPS : 2.00 Features : fp asimd crc32 CPU implementer : 0x41 CPU architecture: 8 CPU variant : 0x0 CPU part : 0xd03 CPU revision : 4 Hardware : ODROID-C2
