Zulus Tips

Today i have spent two hours trying setup synchronization of my Pocket LOOX with Linux desktop PC. Synchronization still not working, but while looking to ‘dmesg‘ output for debugging purposes i have found some interesting AMD Athlon processor features. I knew about frequency scaling before, but i didn’t know what Linux is also has support of AMD CPU Frequency Scaling. I have experience with CPU scaling only on Intel/Centrino processors.

So, i have found this strings:

powernow-k8: Found 1 AMD Athlon 64 / Opteron processors (version 1.50.4)
powernow-k8: 0 : fid 0xe (2200 MHz), vid 0x6 (1400 mV)
powernow-k8: 1 : fid 0xc (2000 MHz), vid 0x8 (1350 mV)
powernow-k8: 2 : fid 0xa (1800 MHz), vid 0xa (1300 mV)
powernow-k8: 3 : fid 0x2 (1000 MHz), vid 0x12 (1100 mV)

Remember my Centrino experience i have look to sysfs for list of available governors. My AMD Athlon 64 support this governors:

# cat \
/sys/devices/system/cpu/cpu0/cpufreq/scaling_available_governors
userspace powersave ondemand conservative performance

Default governor is performance, so CPU works with full power:

# grep MHz /proc/cpuinfo
cpu MHz : 2211.487

But, usually, i don’t need this performance, so i have setup governor value to powersave:

# echo powersave > \
/sys/devices/system/cpu/cpu0/cpufreq/scaling_governor

And now, i have cool & quite CPU ;-)

# grep MHz /proc/cpuinfo
cpu MHz : 1005.221

Now, I’m trying to find some graphic frontend.

This entry was posted on Monday, December 25th, 2006 at 2:14 pm and is filed under Operation Systems, Linux, How-To. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.