07 Jul

How to turn off Power saving A10-5750 on Ubuntu Linux.

On my Laptop Lenovo E545 i have cpu AMD A10-5750. Default cpu speed in CPU-G shows as 1.4 GH. I have decided to turn of power saving (read comments on this post) it on Ubuntu Linux.
First we need Cpu-G utils. Download and install it from repo.

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biotin@ThinkPad:~$ sudo add-apt-repository ppa:cpug-devs/ppa
biotin@ThinkPad:~$ sudo apt-get update
biotin@ThinkPad:~$ sudo apt-get install cpu-g

After running it show us:

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Test Core temperature with ld-sensors:

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biotin@ThinkPad:~$ sensors

k10temp-pci-00c3
Adapter: PCI adapter
temp1:        +45.1°C  (high = +70.0°C)
                       (crit = +100.0°C, hyst = +99.0°C)

More about k10temp here on kernel.org.
Now install cpufrequtils to turn off power saving cpu speed.

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biotin@ThinkPad:~$$ sudo apt-get install cpufrequtils

You can read about cpufregutils here on thinkwiki. It shows as current frequency and we can change it.

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biotin@ThinkPad:~$ sudo cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq
1400000
biotin@ThinkPad:~$ cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_min_freq
1400000
biotin@ThinkPad:~$ cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq
2500000
biotin@ThinkPad:~$ sudo cpufreq-set -c0 -f 2.5Gh
biotin@ThinkPad:~$ sudo cpufreq-set -c1 -f 2.5Gh
biotin@ThinkPad:~$ sudo cpufreq-set -c2 -f 2.5Gh
biotin@ThinkPad:~$ sudo cpufreq-set -c3 -f 2.5Gh
biotin@ThinkPad:~$ sudo cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_cur_freq
2500000

Now run CPU-G.
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I don’t know it work right or nor, but after 5min Core temp show us:

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biotin@ThinkPad:~$ sensors

k10temp-pci-00c3
Adapter: PCI adapter
temp1:        +50.6°C  (high = +70.0°C)
                       (crit = +100.0°C, hyst = +99.0°C)
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  • Robert Ruedisueli

    The temperature should be slightly higher, but not extremely high. This is because the AMD CPUs use microsleep commands as well as processor scaling.

    The 1.4Ghz is the idle speed of your processor, not the speed it runs when power is on. Furthermore, you cannot push the speed higher than the BIOS cap without special kernel modules specific to your motherboard (yes laptops have motherboards). You really only turned off power saving. You didn’t oveclock anything.

    As a note, very little software benefits from turning off processor scaling. Newer processors have very low latency on increasing clock rates under load. Thus, you aren’t going to really see any performance by turning off power saving like this.

    • Biotin

      Thank you for notice. I have changed the Post.

    • biotin

      Thank you for you notice. I have changed the post.