Overclocking
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250 MHz: overall 0.3 %, when not idle 3.0 % | 250 MHz: overall 0.3 %, when not idle 3.0 % | ||
125 MHz: overall 92.5 % | 125 MHz: overall 92.5 % | ||
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| + | =Changing the Kernel= | ||
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| + | ==Installing a modified Kernel== | ||
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| + | Instructions go here | ||
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| + | ==Reverting to the Original Kernel== | ||
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| + | If you want to revert to the original kernel, execute: | ||
| + | |||
| + | apt-get install --reinstall kernel kernel-flasher | ||
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| + | |||
[[Category:Power users]] | [[Category:Power users]] | ||
Revision as of 10:44, 9 April 2010
# WORK IN PROGRESS, HELP IF YOU WANT
Contents |
Warnings
- Overclocking WILL VOID YOUR WARRANTY
- The lifetime of your device will get reduced
- You could lose the data in your device (file system corruption)
- Every device is an individual, what is stable for others might not be for you
- If you encounter ANY unusual problems, lower your clock frequency
- You do it at your own responsibility. No whining afterwards. If you're unsure, don't do it.
Necessary links
talk.maemo.org: Overclock the N900?
talk.maemo.org: Compiling custom kernels for P1.1 (with fiasco-gen)
# ADD IMPORTANT POSTS FROM THE TOPICS
Useful stuff
Show current CPU frequency
awk '{print $1/1000" MHz"}' /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq
Set maximum CPU frequency
From root terminal:
echo $((600*1000)) > /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq
Replace 600 with desired maximum frequency. The list of available frequencies on your device/kernel can be obtained with command:
awk '{print $1/1000" MHz,",$2/1000" MHz,",$3/1000" MHz,",$4/1000" MHz,",$5/1000" MHz"}' /sys/devices/system/cpu/cpu0/cpufreq/scaling_available_frequencies
If the last value returned is 0 MHz, this means that you have only 4 available frequencies.
Analyzing time_in_state
This script generates readable output (percentage) of states used. It is designed for 5 available states. If you have 4 available frequencies (stock kernel) simply remove 7th line and lower "head -n 4" to "head -n 3" in 3rd line.
#!/bin/sh
awk '{print "\nCurrent frequency: "$1/1000" MHz\n"}' /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq
sum=`awk '{SUM += $2} END {print SUM}' /sys/devices/system/cpu/cpu0/cpufreq/stats/time_in_state`
sum2=`cat /sys/devices/system/cpu/cpu0/cpufreq/stats/time_in_state | head -n 4 | awk '{SUM += $2} END {print SUM}'`
cat /sys/devices/system/cpu/cpu0/cpufreq/stats/time_in_state | head -n 1 | awk '{printf (($1/1000)" MHz: overall "); printf ("%.1f",($2 * 100)/"'"$sum"'"); printf ("'" %%, when not idle "'"); printf ("%.1f %\n",($2 * 100)/"'"$sum2"'")}'
cat /sys/devices/system/cpu/cpu0/cpufreq/stats/time_in_state | head -n 2 | tail -n 1 | awk '{printf (($1/1000)" MHz: overall "); printf ("%.1f",($2 * 100)/"'"$sum"'"); printf ("'" %%, when not idle "'"); printf ("%.1f %\n",($2 * 100)/"'"$sum2"'")}'
cat /sys/devices/system/cpu/cpu0/cpufreq/stats/time_in_state | head -n 3 | tail -n 1 | awk '{printf (($1/1000)" MHz: overall "); printf ("%.1f",($2 * 100)/"'"$sum"'"); printf ("'" %%, when not idle "'"); printf ("%.1f %\n",($2 * 100)/"'"$sum2"'")}'
cat /sys/devices/system/cpu/cpu0/cpufreq/stats/time_in_state | head -n 4 | tail -n 1 | awk '{printf (($1/1000)" MHz: overall "); printf ("%.1f",($2 * 100)/"'"$sum"'"); printf ("'" %%, when not idle "'"); printf ("%.1f %\n",($2 * 100)/"'"$sum2"'")}'
cat /sys/devices/system/cpu/cpu0/cpufreq/stats/time_in_state | tail -n 1 | awk '{printf (($1/1000)" MHz: overall "); printf ("%.1f %\n\n",($2 * 100)/"'"$sum"'")}'
Output example:
Current frequency: 125 MHz 800 MHz: overall 5.0 %, when not idle 70.0 % 550 MHz: overall 0.2 %, when not idle 2.0 % 500 MHz: overall 2.0 %, when not idle 25.0 % 250 MHz: overall 0.3 %, when not idle 3.0 % 125 MHz: overall 92.5 %
Changing the Kernel
Installing a modified Kernel
Instructions go here
Reverting to the Original Kernel
If you want to revert to the original kernel, execute:
apt-get install --reinstall kernel kernel-flasher