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==Reminders==

This page is about overclocking and undervolting the [[Nokia N900|N900]]. For the N8x0 see [http://talk.maemo.org/showthread.php?t=12464 this thread on talk.maemo.org]

Overclocking is discussed in [http://talk.maemo.org/showthread.php?t=39753 this thread]. Benchmark results can be found [http://talk.maemo.org/showthread.php?p=605189 here]. If you're more interested in power saving read [http://talk.maemo.org/showthread.php?t=49654 this].

This guide focuses on kernel-power v50 and above, as it introduces improvements in stability and maximum supported frequency for SmartReflex, making it highly desirable for a Maemo system that is overclocked 24/7.

==Warnings==

* Overclocking WILL VOID YOUR WARRANTY. Your warranty does not cover running the device beyond the specifications.
* The lifetime of your device WILL get reduced as a result of [[:wikipedia:Electromigration electromigration]]
* Your device might not perform properly - bizarre bugs and corruption may result from the CPU being physically unable to cope with higher frequencies (see the next point)
* All devices are not made equal - some may be able to handle 1.15GHz daily just fine, while some may be unstable even at 720MHz.
* You do it at your own responsibility. No whining afterwards. If you're unsure, don't do it.
* [http://depot.javispedro.com/nit/thewarningtm.jpeg Nokia's overclocking warning]: 500 MHz is the normal frequency. Everything above is not good for your device, even with the stock kernel.
* Igor Stoppa's [http://talk.maemo.org/showpost.php?p=596149&postcount=904 warning] and [http://talk.maemo.org/showpost.php?p=603833&postcount=66 comment]
* [http://talk.maemo.org/showpost.php?p=596274&postcount=937 chip vendors specs]

==Lifetime, warranty and damage==

* The expected lifetime '''all''' devices is limited due to wear.
* It is usually much longer (several years) than the warranty period, so that even with heavy use within the specifications it would not fail before warranty ends.
* With overclocking users may see considerable speed improvements and lower latency in user experience which could extend the actual lifetime (of being used) as the device could keep up with the newer models.
* Excessive overclocking with stock voltages is definitely bad for most components in your device, especially if the device is continuously locked at high frequencies with high load (see TI specs).
* Specifications give guarantees for the worst-case scenarios that are covered by the warranty. The best-case scenario may be different for every device but is not covered by warranty.
* However, there is an open debate whether '''mild''' (<40%) overclocking with lower voltages (undervolting) does actually harm or is even less harmful than the stock settings. See [[#Undervolting and voltage tables]] for an explanation why undervolting in fact won't help anything due to chip using SmartReflex Technology (which can not be disabled).
* Evidence for or against damages (esp. with undervolting) in the N900 is currently absent and will probably only be available when the device is no longer on the market. Or you decide to acquire thorough electronics engineer's understanding of the issue, and study TI's papers regarding SmartReflex™ and how it works - then all the evidence for damage positively done is there already.
* Therefore, if you are unsure and you want to avoid potential damages, do not overclock!

==Overclocking, bugzilla & errors==

* Running a device overclocked for long periods of time could produce unwanted side effects, even persisting ones that won't revert when overclocking is stopped. If you are experiencing errors following overclocking and intend to report those errors to talk.maemo.org or bugzilla, please consider the following :
** Errors induced by overclocking will not always appear to be as such.
** It will be considered a good idea to reproduce your error / problem on a device which has never been overclocked AT ALL, before proceeding with actions regarding your problem.
** In the event you have decided to file a bug report or open a thread about your problem, please add a note to that report, mentioning that you are or previously were in fact running your device overclocked.  Please also provide details about the period and amount of overclocking used.
* The reason for these requirements is that there are many problems pending for developer's attention. It is a huge waste of time to try and trace down an error without knowing all the facts, just to find out in the end that the particular problem was caused by a damaged hardware. If the developers know about it, they can take it into account and won't rule out a 1+1=3 problem on the reporter's device during their analysis.

==Available kernels==

Overclocking requires installation of a custom kernel. There are two types of kernels:
# [[Kernel_Power|kernel-power]], developed by Titan and maintained by Pali '''(highly recommended)'''. They are compatible with [[Maemo 5/PR1.2|PR1.2]] and [[Maemo 5/PR1.3|PR1.3]], contain lots of additional features (IPv6, NAT etc) and bugfixes. In addition, they include a large set of possible frequencies (125 MHz-1.15 GHz) which can be manually set and tested without flashing a new kernel. The defaults are set to the standard 250-600 MHz range. 
This guide recommends using kernel-power v50, which at the time of writing is available in the [[extras]] catalog. Newer, more experimental kernels may be available through [[extras-testing]] or [[extras-devel]].
# Modified [[Maemo 5/PR1.1|PR1.1]] kernels by Lehto and others. The only difference from the stock Nokia kernel is the change of the available hardcoded frequencies.

==Additional information and hints==

# The stock Nokia kernel uses the following frequencies: 250, 500, 550 and 600 MHz.
# The CPU does '''NOT IDLE''' at the lowest frequency (250 MHz) but it '''SLEEPS''' at 0 MHz! Thus, reducing the lowest frequency would not reduce power consumption. It is only activated during low workload and may actually consume more power than a higher frequency, as it takes more time to go back to sleep/idle state.
# Setting the lowest frequency to 125 MHz does NOT improve battery life. In fact, many people noticed worse battery life, instability and worse responsiveness,
# The Phone app is closed-source and broken. During a phone call, the device's frequency [http://talk.maemo.org/showpost.php?p=601691&postcount=1823 is locked to 600MHz]. This may be a bug, and it affects all kernels for Fremantle. After a phone call, it sets the maximum to 600 Mhz and the minimum to 250 MHz (or 125 MHz if available) regardless of the frequencies you have set. There are some workarounds present in kernel-power, however the bug may still occasionally manifest.
# when connected via USB the device locks the minimum frequency to 500 Mhz.
# By default the device is configured to use 125 MHz as the lowest frequency but it not enabled in the kernel [https://bugs.maemo.org/show_bug.cgi?id=7116 pmconfig bug]
# The warning <pre>WARNING: at arch/arm/mach-omap2/clock34xx.c:443 omap3_noncore_dpll_set_rate+0x28c/0x2dc()</pre> in the kernel logs (dmesg) only happens if the invalid 800 MHz frequency was selected. Ignore it.
# EvilJazz had photoshopped a [http://talk.maemo.org/showpost.php?p=605523&postcount=90 picture of a device being overclocked 1.7GHz]. It's a '''prank'''!
# The internal temperature sensor may be read by using the command "cat /sys/devices/platform/omap34xx_temp/temp1_input"
'''Note that the system does not have an on-die temperature sensor, and the actual CPU temperature may be higher or lower than the reading.'''

==Installing a modified kernel==

===Kernel-Power===
====Installing from the repositories====
# Open the Application Manager
# Go to the "System" section, and install the package kernel-power-settings. This automatically pulls in the rest of kernel-power as dependencies.
# After successful installation, reboot the device.

===Lehto's Kernel and other legacy kernels===

====Flashing from X Terminal====

* do a backup, have a PC nearby and know you are able to flash the N900 with flasher-3.5 - just in case

# Launch xterminal app then type sudo gainroot (need rootsh installed)
# Type:<pre>softupd -vv -s --local</pre>(that is a double v)
# Open new terminal
# Type:<pre>flasher --local -f -k <kernel_zimage_file_with_path></pre>
# You'll see the flashing (takes some time)
# Type "sync" to save changes
# Type "reboot" and enter to restart
# Test out your phone as usual. (Apps, browser, camera, phone etc etc)
# If any abnormal events occur frequently (crash, hang, screen corruption etc), turn it off, flash it to a slower kernel and test again.

===Reverting to the Stock Kernel===

If you want to revert to the stock Nokia kernel, execute:

apt-get install --reinstall kernel kernel-flasher

in X Terminal.

=== Fixing the version information ===

If your version information got lost (control panel -> version) you can fix it by reinstalling the package that is listed with:
 dpkg -l "mp-fremantle*"
for example, "mp-fremantle-generic-pr" (for some firmwares 002 or 003 instead of generic) and then execute:
 apt-get install --reinstall mp-fremantle-generic-pr

==Overclocking==
Once you have installed kernel-power, you are ready to start overclocking.
# List available frequencies ("active frequencies")<pre> sudo kernel-config show </pre>
# Select the lowest and highest frequencies to be used from the list of active frequencies,  The kernel will use all '''active frequencies''' between and including those you selected.
# The following command will set the frequencies to stock:<pre> sudo kernel-config limits 250 600 </pre>
# The following command will set the maximum to the highest supported by '''SmartReflex'''. (Note that SmartReflex in kernel-power v50 only works with frequencies up to 900MHz.)<pre> sudo kernel-config limits 250 900 </pre>
# At this point, you should test system stability by launching a few programs, browsing JavaScript-heavy webpages, and playing a movie.
# Should you encounter no reboots, you can save your overclocking profile.<pre> sudo kernel-config save myprofile </pre>
# You can now proceed to set your kernel profile as the default, to be loaded automatically at startup.<pre> sudo kernel-config default myprofile </pre>

==Undervolting==

===SmartReflex===

====Rationale====
Before kernel-power v50, one would normally set voltages per frequency in a configuration file, which required manual testing to determine the lowest voltages possible for a specific frequency. This may result in reboots if the voltage was not set high enough to account for the CPU's power usage at full loads, or power wastage if the voltages were set higher than what is needed for light loads at a certain frequency.
SmartReflex is a technology which automatically regulates the voltage used for the entire SoC, automatically adapting to lower voltages during light use and increase them during heavy use.

====Automatic Undervolting====
Once kernel-power v50 or higher is installed, enabling it is a matter of doing the following:
# Make a folder for your kernel profiles<pre> mkdir -p ~/.kernel </pre>
# Copy a sane profile to your kernel profile folder<pre> cp /usr/share/kernel-power-settings/default ~/.kernel/myprofile </pre>
# Edit the profile to enable SmartReflex<pre> nano ~/.kernel/myprofile </pre>
# Look for the lines:<pre> SMARTREFLEX_VDD1=0 SMARTREFLEX_VDD2=0</pre>
# Edit them to the following:<pre>SMARTREFLEX_VDD1=1 SMARTREFLEX_VDD2=1</pre>
# Save the file by pressing Ctrl+X, and confirm with Y then press Enter.
# Test the profile<pre> sudo kernel-config load myprofile </pre>
# At this point, you'd want to stress the CPU a bit. Launch a few programs, visit JS-heavy websites, etc.
# If the device does not reboot and you feel safe using the profile, set it as the default.<pre> sudo kernel-config default myprofile </pre>
# Congratulations, the kernel is now doing all the work for you.

===Manual Undervolting (Legacy)===

====Undervolting and voltage tables====

See: http://talk.maemo.org/showpost.php?p=628839&postcount=81

Extract from the post:

<pre>CPU power consumption (without constants) = leakage + capacitance + switching = voltage^2 + frequency + (voltage^2 * frequency)</pre>

One factor reducing CPU lifetime is the current it is running with [[:wikipedia:Dynamic_frequency_scaling|dynamic frequency scaling]].
<pre>CPU dynamic power consumption = capacitance * frequency * voltage^2</pre>

As can be seen from the formula, lower voltage plays greater part in CPU consumption than frequency. By reducing the voltage the damage of overclocking can be reduced and the battery life time extended. Alas, this claim only holds true for architectures not regulating the real voltage and current in special on chip regulators, like OMAP is known to do for almost every gate in their CPU and other SoC function blocks. TI calls this feature SmartReflex™ and lowering the voltage applied to the whole SoC, like suggested here, only reduces the voltage drop across these regulators, thus no positive effect on electromigration damage ([[:wikipedia:Electromigration]]) caused by overclocking is to be expected.

====Calculating voltages====

According to [http://talk.maemo.org/showpost.php?p=606031&postcount=2375 this calculations] the voltage can be varied in steps of 0.0125 V with values 0-72. The formula is (with x being the kernel parameter value):

Examples:

Lowest voltage (x = 0):   0  * 0.0125 + 0.6 = 0     + 0.6 = 0.6 V
 Highest voltage (x = 72): 72 * 0.0125 + 0.6 = 0.9   + 0.6 = 1.5 V
 Random voltage (x = 38):  38 * 0.0125 + 0.6 = 0.475 + 0.6 = 1.075 V

=====Voltage Step Tables=====

FREQUENCY   Nokia   LV    ULV   XLV   ideal   starving
 0 MHz       30      30    25    30    30      22
 125 MHz     30      30    25    20    30      22
 250 MHz     38      38    25    30    30      28
 500 MHz     48      48    33    33    30      29
 550 MHz    *54*     48    38    38    33      32
 600 MHz     60     *54*   38    38    38      34
 700 MHz             54    45    45    45      41
 750 MHz             54    45    45    45      42
 810 MHz             54    48    48    48      45
 850 MHz             54    48    48    48      46
 900 MHz             54   *54*  *54*  *54*     49
 950 MHz             54    54    54    54      52
 1000 MHz            60    60    60    60      55
 1100 MHz            72    72    72    72      63
 1150 MHz            72    72    72    72      69

Note: Asterisks indicate the first frequency in the kernel which needs overvoltage.

=====Actual Voltage Tables=====

======Nokia's kernel======

VALUE  VOLTAGE   FREQUENCY     DYNAMIC POWER
 30     0.975 V   0 MHz         0.000 V²/us
 30     0.975 V   125 MHz       118.828 V²/us
 38     1.075 V   250 MHz       288.906 V²/us
 48     1.200 V   500 MHz       720.000 V²/us
 54     1.275 V   550 MHz       894.094 V²/us
 60     1.350 V   600 MHz       1093.500 V²/us

======kernel-power LV profile======

VALUE  VOLTAGE   FREQUENCY     DYNAMIC POWER
 30     0.975V    0 MHz         0.000 V²/us
 30     0.975V    125 MHz       118.828 V²/us
 38     1.075V    250 MHz       288.906 V²/us
 48     1.200V    500 MHz       720.000 V²/us
 48     1.200V    550 MHz       792.000 V²/us
 54     1.275V    600 MHz       975.375 V²/us
 54     1.275V    700 MHz       1137.938 V²/us
 54     1.275V    750 MHz       1219.219 V²/us
 54     1.275V    810 MHz       1316.756 V²/us
 54     1.275V    850 MHz       1381.781 V²/us
 54     1.275V    900 MHz       1463.062 V²/us
 54     1.275V    950 MHz       1544.344 V²/us
 60     1.350V    1000 MHz      1822.500 V²/us
 72     1.500V    1100 MHz      2475.000 V²/us
 72     1.500V    1200 MHz      2700.000 V²/us

======kernel-power ULV profile======

VALUE  VOLTAGE   FREQUENCY    DYNAMIC POWER
 25     0.912V    0 MHz        0.000 V²/us
 25     0.912V    125 MHz      103.968 V²/us
 25     0.912V    250 MHz      207.936 V²/us
 33     1.012V    500 MHz      512.072 V²/us
 38     1.075V    550 MHz      635.594 V²/us
 38     1.075V    600 MHz      693.375 V²/us
 45     1.163V    700 MHz      946.798 V²/us
 45     1.163V    750 MHz      1014.427 V²/us
 48     1.200V    810 MHz      1166.400 V²/us
 48     1.200V    850 MHz      1224.000 V²/us
 54     1.275V    900 MHz      1463.062 V²/us
 54     1.275V    950 MHz      1544.344 V²/us
 60     1.350V    1000 MHz     1822.500 V²/us
 72     1.500V    1100 MHz     2475.000 V²/us
 72     1.500V    1200 MHz     2700.000 V²/us

======kernel-power XLV profile======

VALUE  VOLTAGE   FREQUENCY    DYNAMIC POWER
 30     0.975V    0 MHz        0.000 V²/us
 20     0.850V    125 MHz      90.312 V²/us
 30     0.975V    250 MHz      237.656 V²/us
 33     1.012V    500 MHz      512.072 V²/us
 38     1.075V    550 MHz      635.594 V²/us
 38     1.075V    600 MHz      693.375 V²/us
 45     1.163V    700 MHz      946.798 V²/us
 45     1.163V    750 MHz      1014.427 V²/us
 48     1.200V    810 MHz      1166.400 V²/us
 48     1.200V    850 MHz      1224.000 V²/us
 54     1.275V    900 MHz      1463.062 V²/us
 54     1.275V    950 MHz      1544.344 V²/us
 60     1.350V    1000 MHz     1822.500 V²/us
 72     1.500V    1100 MHz     2475.000 V²/us
 72     1.500V    1150 MHz     2587.500 V²/us

======kernel-power "ideal" profile======

VALUE  VOLTAGE   FREQUENCY    DYNAMIC POWER
 30     0.975V    0 MHz        0.000 V²/us
 30     0.975V    125 MHz      118.828 V²/us
 30     0.975V    250 MHz      237.656 V²/us
 30     0.975V    500 MHz      475.312 V²/us
 33     1.012V    550 MHz      563.279 V²/us
 38     1.075V    600 MHz      693.375 V²/us
 45     1.163V    700 MHz      946.798 V²/us
 45     1.163V    750 MHz      1014.427 V²/us
 48     1.200V    810 MHz      1166.400 V²/us
 48     1.200V    850 MHz      1224.000 V²/us
 54     1.275V    900 MHz      1463.062 V²/us
 54     1.275V    950 MHz      1544.344 V²/us
 60     1.350V    1000 MHz     1822.500 V²/us
 72     1.500V    1100 MHz     2475.000 V²/us
 72     1.500V    1150 MHz     2587.500 V²/us

==Useful scripts==

===Analyze kernel system frequency use percentage===
Written by ''rooted''

''I've stopped the development of this script and I hope someone will make use of the code. I hope titan includes it in "kernel-config show" or "kernel-config debug". -rooted''

This script prints percentage of frequencies (states) used and some additional info useful for posting on the forum (debugging). It displays all frequencies, works with all kernels and it is not affected by the bug which resets minimum frequency after phone call.

Temperature may not be listed if you don't have module bq27x00_battery installed or enabled. Also kernel-power version is not listed if you don't use titan's kernel.

<source lang="bash">
#!/bin/sh

idlefreq=`awk '{if ($2 > 0) print $1}' /sys/devices/system/cpu/cpu0/cpufreq/stats/time_in_state | tail -n 1`
tis1=`awk '{sum += $2} END {print sum}' /sys/devices/system/cpu/cpu0/cpufreq/stats/time_in_state`
tis2=`awk '$1 == "'"$idlefreq"'" {idle = $2} {sum += $2} END {print sum-idle}' /sys/devices/system/cpu/cpu0/cpufreq/stats/time_in_state`

echo -e "
TIME_IN_STATE ANALYSING SCRIPT
By rooted (maemo.org)
Revision 7
wiki.maemo.org/Overclocking

FREQUENCY\tUSED\t\tWHEN BUSY\n"
awk '
{if ($1 >= 1000000)                 printf ("%.0f MHz\t",$1/1000); else printf ("%.0f MHz\t\t",$1/1000)}
{if ($2 == 0)                       printf "unused";               else printf ("%.1f %\t\t",($2*100)/"'"$tis1"'")}
{if ($2 == 0 || $2/"'"$tis2"'" > 1) printf "\n";                   else printf ("%.1f %\n",($2*100)/"'"$tis2"'")}
' /sys/devices/system/cpu/cpu0/cpufreq/stats/time_in_state

echo -e "
Kernel:                  `uname -r`
kernel-power:            `dpkg -l kernel-power | awk '$2 == "kernel-power" {print $3}'`
kernel-power-settings:   `dpkg -l kernel-power-settings | awk '$2 == "kernel-power-settings" {print $3}'`
Uptime:                  `uptime | sed -e 's/.*p *//' -e 's/, l.*//' -e 's/  / /'`
Load:                    `uptime | sed 's/.*e: //'`
Boot reason:             `cat /proc/bootreason`
Temperature:             `cat /sys/class/power_supply/bq27200-0/temp` degrees C\n"
</source>

Output example:

<pre>TIME_IN_STATE ANALYSING SCRIPT
By rooted (maemo.org)
Revision 7
wiki.maemo.org/Overclocking

FREQUENCY       USED            WHEN BUSY

1150 MHz        unused
1100 MHz        unused
1000 MHz        unused
950 MHz         unused
900 MHz         unused
850 MHz         unused
805 MHz         4.5 %           58.9 %
750 MHz         0.0 %           0.4 %
700 MHz         0.0 %           0.3 %
600 MHz         0.3 %           3.4 %
550 MHz         0.0 %           0.5 %
500 MHz         2.8 %           36.5 %
250 MHz         92.4 %
125 MHz         unused

Kernel:                  2.6.28.10power37
kernel-power:            2.6.28-maemo37
kernel-power-settings:   0.11
Uptime:                  56 min
Load:                    0.25, 0.12, 0.09
Boot reason:             pwr_key
Temperature:             31 degrees C</pre>

===Analyze kernel system frequency use percentage, including idle mode stats===
Written by ''ArbitRabbit''

The following script will show the current frequency and statistics for each state, including time spent in idle mode when the CPU is actually sleeping. This script works with the special frequency handling in Titan's kernel.

To run this script as user and be able to set the frequencies you will need to install "[[Root_access|rootsh]]" via apt-get.

'''scheduler_stats.sh'''
<source lang="bash">
#!/bin/sh
awk '{print "\nCurrent frequency: "$1/1000" MHz\n"}' /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq
awk '{print "Minimum frequency: "$1/1000" MHz\n"}' /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq
awk '{print "Maximum frequency: "$1/1000" MHz\n"}' /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq

tis1=`awk '{SUM += $2} END {printf("%.0f",SUM/1000)}' /sys/devices/system/cpu/cpu0/cpufreq/stats/time_in_state`

idle0=`awk '{printf ("%.0f",$1/1000)}' /sys/devices/system/cpu/cpu0/cpuidle/state0/time`

idle1=`awk '{printf ("%.0f",$1/1000)}' /sys/devices/system/cpu/cpu0/cpuidle/state1/time`

idle2=`awk '{printf ("%.0f",$1/1000)}' /sys/devices/system/cpu/cpu0/cpuidle/state2/time`

idle3=`awk '{printf ("%.0f",$1/1000)}' /sys/devices/system/cpu/cpu0/cpuidle/state3/time`

totaltime=$(($idle0+$idle1+$idle2+$idle3+$tis1))
echo -e "FREQUENCY\tUSED"
SUM=0
awk '
       {
               printf (($1/1000)" MHz \t");
               if ($2 == 0)
               {
                       printf "0 %\n";
               }
               else {
                       SUM+=$2;
                       printf("%.3f %\n",($2/10)/"'"$totaltime"'");
                       }
       }
       END{
       printf ("Time spent in idle mode is %2.2f %\n",(1-((SUM/1000)/"'"$totaltime"'"))*100);
       }' /sys/devices/system/cpu/cpu0/cpufreq/stats/time_in_state
echo ""
</source>

'''Sample Output'''

<pre>Current frequency: 500 MHz

Minimum frequency: 500 MHz

Maximum frequency: 810 MHz

FREQUENCY       USED
1200 MHz        0 %
1100 MHz        0 %
1000 MHz        0 %
950 MHz         0 %
900 MHz         0 %
850 MHz         0 %
810 MHz         0.000 %
750 MHz         0.000 %
700 MHz         0.000 %
600 MHz         0.000 %
550 MHz         0.000 %
500 MHz         0.010 %
Time spent in idle mode is 99.99 %</pre>

Known Bugs: Requires the Phone to be booted for an hour or so before it results in decent stats.

===Combined helper script===
Written by ''EvilJazz''

The following script will show the current frequency and statistics. It also accepts two optional parameters that will set the max and/or min frequencies (in MHz unit). Calling the script without these parameters will not set the new clocking. Instead it will just show the current frequencies and statistics.

This script works with the special frequency handling in Titan's kernel.

To run this script as user and be able to set the frequencies you will need to install "[[Root_access|rootsh]]" via apt-get.

overclock.sh [max freq] [min freq]

<source lang="bash">
#!/bin/sh
max=${1}000
min=${2}000

# Handle and rewrite special cases in Titan's kernel...
[ "$max" == "600000" ] && max=599000
[ "$min" == "125000" ] && min=124999

if [ $(id -u) -ne 0 ]; then
  [ "$max" != "000" ] && echo "echo $max > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq" | sudo gainroot
  [ "$min" != "000" ] && echo "echo $min > /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq" | sudo gainroot
else
  [ "$max" != "000" ] && echo $max > /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq
  [ "$min" != "000" ] && echo $min > /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq
fi

awk '{printf("\nCurrent frequency: %7s MHz\n", $1/1000)}' /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq
awk '{printf("Minimal frequency: %7s MHz\n", $1/1000)}' /sys/devices/system/cpu/cpu0/cpufreq/scaling_min_freq
awk '{printf("Maximal frequency: %7s MHz\n\n", $1/1000)}' /sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq

sum=$(awk '{SUM += $2} END {print SUM}' /sys/devices/system/cpu/cpu0/cpufreq/stats/time_in_state)
awk '{printf("%7s MHz: %5.1f % (%8d)\n", ($1/1000), ($2 * 100)/"'"$sum"'", $2)}' /sys/devices/system/cpu/cpu0/cpufreq/stats/time_in_state
echo
</source>

Output example:

<pre>~ $ ./overclock.sh 600 250

Current frequency:     250 MHz
Minimal frequency:     250 MHz
Maximal frequency:     599 MHz

1200 MHz:   0.0 % (       0)
   1100 MHz:   0.0 % (       0)
   1000 MHz:   0.0 % (       0)
    950 MHz:   0.0 % (       0)
    900 MHz:   0.2 % (     271)
    850 MHz:   0.0 % (       0)
    810 MHz:   0.0 % (       0)
    750 MHz:   0.0 % (       0)
    700 MHz:   0.0 % (       0)
    600 MHz:   9.0 % (   13663)
    550 MHz:   0.5 % (     701)
    500 MHz:  15.4 % (   23379)
    250 MHz:  75.0 % (  114021)
124.999 MHz:   0.0 % (       0)</pre>

===Underclock/Overclock when phone is locked/unlocked===
Written by ''Fecn''

When locked, the limits are changed to 250/500 Mhz to save power - I don't need my phone to be fast when it's sitting there doing nothing. (I did try with 125 Mhz as minimum but it caused an unresponsive touchscreen during incoming phone calls and alarms)

When unlocked, the limits are set for overclocking, with the max speed determined by the temperature (1150 Mhz is stable on my phone - your mileage may vary - adjust scripts as required)

You need the dbus-scripts package installed for this to work. You also need to add bq27x00_battery to your /etc/modules so that it is loaded at boot time - it needs to be loaded to be able to read the temperature.

Note by --[[User:joerg_rw|joerg_rw]] 18:03, 2 August 2010 (UTC):
Which temperature are you trying to base that on? Anyway the bq27200 temperature is vastly useless for this purpose, as it is the die (chip) temperature of the battery charge gauge, and neither related to CPU die temperature, nor to battery cell temperature.

We use the dbus-signalling to follow what the phone is doing and fire off scripts to change the limits accordingly.

Create the following two 1-line files inside /etc/dbus-scripts.d/  (before you need to install the dbus-scripts package)

<pre>
Filename: /etc/dbus-scripts.d/locked 
/usr/local/bin/underclock * * com.nokia.mce.signal tklock_mode_ind locked

Filename: /etc/dbus-scripts.d/unlocked
/usr/local/bin/overclock * * com.nokia.mce.signal tklock_mode_ind unlocked
</pre>

... and then create corresponding scripts that they call inside /usr/local/bin/ ( don't forget to chmod them to executable )

<pre>
Filename: /usr/local/bin/underclock 
#!/bin/sh
kernel-config limits 250 500

Filename: /usr/local/bin/overclock  
#!/bin/sh
TEMP=`cat /sys/class/power_supply/bq27200-0/temp`
echo "Temp is :" $TEMP "C"
MAXSPEED="1150"
if [ $TEMP -gt "38" ] ; then MAXSPEED="1000" ; fi
if [ $TEMP -gt "40" ] ; then MAXSPEED="950" ; fi
if [ $TEMP -gt "43" ] ; then MAXSPEED="850" ; fi
if [ $TEMP -gt "45" ] ; then MAXSPEED="750" ; fi
if [ $TEMP -gt "47" ] ; then MAXSPEED="600" ; fi
echo "Setting max as :" $MAXSPEED "Mhz"

kernel-config limits 250 $MAXSPEED
</pre>

You'll need to restart dbus-scripts for it to see the new configs. I found that the scripts in init.d weren't too good at doing this, so had to kill it manually each time.

If you want to scale your processor speed according to battery capacity in addition to temperature, use an overclock script something like the following:

<pre>
Filename: /usr/local/bin/overclock
#!/bin/sh
TEMP=`cat /sys/class/power_supply/bq27200-0/temp`
echo "Temp is:" $TEMP "C"
MAXSPEED="1150"
if [ $TEMP -gt "38" ] ; then MAXSPEED="1000" ; fi
if [ $TEMP -gt "40" ] ; then MAXSPEED="950" ; fi
if [ $TEMP -gt "43" ] ; then MAXSPEED="850" ; fi
if [ $TEMP -gt "45" ] ; then MAXSPEED="750" ; fi
if [ $TEMP -gt "47" ] ; then MAXSPEED="600" ; fi

BATTERY=`cat /sys/class/power_supply/bq27200-0/capacity`
echo "Battery is:" $BATTERY "% full"
MAXSPEEDTWO="1150"
if [ $BATTERY -lt "60" ] ; then MAXSPEEDTWO="850" ; fi
if [ $BATTERY -lt "40" ] ; then MAXSPEEDTWO="600" ; fi
if [ $BATTERY -lt "25" ] ; then MAXSPEEDTWO="500" ; fi

if [ $MAXSPEEDTWO -lt $MAXSPEED ] ; then MAXSPEED=$MAXSPEEDTWO ; fi

echo "Setting max as:" $MAXSPEED "Mhz"

kernel-config limits 250 $MAXSPEED
</pre>

[[Category:Power users]]
[[Category:N900]]

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@@ Line 10: / Line 10: @@
 * Overclocking WILL VOID YOUR WARRANTY. Your warranty does not cover running the device beyond the specifications.
-* The lifetime of your device WILL get reduced as a result of [[:wikipedia:Electromigration]]
+* The lifetime of your device WILL get reduced as a result of [[:wikipedia:Electromigration electromigration]]
 * Your device might not perform properly - bizarre bugs and corruption may result from the CPU being physically unable to cope with higher frequencies (see the next point)
 * All devices are not made equal - some may be able to handle 1.15GHz daily just fine, while some may be unstable even at 720MHz.
 * You do it at your own responsibility. No whining afterwards. If you're unsure, don't do it.
-* Nokia's overclocking warning: 500 MHz is the normal frequency. Everything above is not good for your device, even with the stock kernel.
+* [http://depot.javispedro.com/nit/thewarningtm.jpeg Nokia's overclocking warning]: 500 MHz is the normal frequency. Everything above is not good for your device, even with the stock kernel.
 * Igor Stoppa's [http://talk.maemo.org/showpost.php?p=596149&postcount=904 warning] and [http://talk.maemo.org/showpost.php?p=603833&postcount=66 comment]
 * [http://talk.maemo.org/showpost.php?p=596274&postcount=937 chip vendors specs]
@@ Line 36: / Line 36: @@
 ** In the event you have decided to file a bug report or open a thread about your problem, please add a note to that report, mentioning that you are or previously were in fact running your device overclocked.  Please also provide details about the period and amount of overclocking used.
 * The reason for these requirements is that there are many problems pending for developer's attention. It is a huge waste of time to try and trace down an error without knowing all the facts, just to find out in the end that the particular problem was caused by a damaged hardware. If the developers know about it, they can take it into account and won't rule out a 1+1=3 problem on the reporter's device during their analysis.
+==Available kernels==
+Overclocking requires installation of a custom kernel. There are two types of kernels:
+# [[Kernel_Power|kernel-power]], developed by Titan and maintained by Pali '''(highly recommended)'''. They are compatible with [[Maemo 5/PR1.2|PR1.2]] and [[Maemo 5/PR1.3|PR1.3]], contain lots of additional features (IPv6, NAT etc) and bugfixes. In addition, they include a large set of possible frequencies (125 MHz-1.15 GHz) which can be manually set and tested without flashing a new kernel. The defaults are set to the standard 250-600 MHz range.
+This guide recommends using kernel-power v50, which at the time of writing is available in the [[extras]] catalog. Newer, more experimental kernels may be available through [[extras-testing]] or [[extras-devel]].
+# Modified [[Maemo 5/PR1.1|PR1.1]] kernels by Lehto and others. The only difference from the stock Nokia kernel is the change of the available hardcoded frequencies.
 ==Additional information and hints==
-* The stock Nokia kernel uses the following frequencies: 250, 500, 550 and 600 MHz.
+# The stock Nokia kernel uses the following frequencies: 250, 500, 550 and 600 MHz.
-* The CPU does '''NOT IDLE''' at the lowest frequency (250 MHz) but it '''SLEEPS''' at 0 MHz! Thus, reducing the lowest frequency would not reduce power consumption. It is only activated during low workload and may actually consume more power than a higher frequency, as it takes more time to go back to sleep/idle state.
+# The CPU does '''NOT IDLE''' at the lowest frequency (250 MHz) but it '''SLEEPS''' at 0 MHz! Thus, reducing the lowest frequency would not reduce power consumption. It is only activated during low workload and may actually consume more power than a higher frequency, as it takes more time to go back to sleep/idle state.
-* Setting the lowest frequency to 125 MHz does NOT improve battery life. In fact, many people noticed worse battery life, instability and worse responsiveness,
+# Setting the lowest frequency to 125 MHz does NOT improve battery life. In fact, many people noticed worse battery life, instability and worse responsiveness,
-* The Phone app is closed-source and broken. During a phone call, the device's frequency [http://talk.maemo.org/showpost.php?p=601691&postcount=1823 is locked to 600MHz]. This may be a bug, and it affects all kernels for Fremantle. After a phone call, it sets the maximum to 600 Mhz and the minimum to 250 MHz (or 125 MHz if available) regardless of the frequencies you have set. There are some workarounds present in kernel-power, however the bug may still occasionally manifest.
+# The Phone app is closed-source and broken. During a phone call, the device's frequency [http://talk.maemo.org/showpost.php?p=601691&postcount=1823 is locked to 600MHz]. This may be a bug, and it affects all kernels for Fremantle. After a phone call, it sets the maximum to 600 Mhz and the minimum to 250 MHz (or 125 MHz if available) regardless of the frequencies you have set. There are some workarounds present in kernel-power, however the bug may still occasionally manifest.
-* When connected via USB the device locks the minimum frequency to 500 Mhz.
+# when connected via USB the device locks the minimum frequency to 500 Mhz.
-* By default the device is configured to use 125 MHz as the lowest frequency but it not enabled in the kernel [https://bugs.maemo.org/show_bug.cgi?id=7116 pmconfig bug]
+# By default the device is configured to use 125 MHz as the lowest frequency but it not enabled in the kernel [https://bugs.maemo.org/show_bug.cgi?id=7116 pmconfig bug]
-* The warning <pre>WARNING: at arch/arm/mach-omap2/clock34xx.c:443 omap3_noncore_dpll_set_rate+0x28c/0x2dc()</pre> in the kernel logs (dmesg) only happens if the invalid 800 MHz frequency was selected. Ignore it.
+# The warning <pre>WARNING: at arch/arm/mach-omap2/clock34xx.c:443 omap3_noncore_dpll_set_rate+0x28c/0x2dc()</pre> in the kernel logs (dmesg) only happens if the invalid 800 MHz frequency was selected. Ignore it.
-* EvilJazz had photoshopped a [http://talk.maemo.org/showpost.php?p=605523&postcount=90 picture of a device being overclocked 1.7GHz]. It's a '''prank'''!
+# EvilJazz had photoshopped a [http://talk.maemo.org/showpost.php?p=605523&postcount=90 picture of a device being overclocked 1.7GHz]. It's a '''prank'''!
-* The internal temperature sensor may be read by using the command "cat /sys/devices/platform/omap34xx_temp/temp1_input"
+# The internal temperature sensor may be read by using the command "cat /sys/devices/platform/omap34xx_temp/temp1_input"
-* '''Note''' that the system does not have an on-die temperature sensor, and the actual CPU temperature may be higher or lower than the reading.
+'''Note that the system does not have an on-die temperature sensor, and the actual CPU temperature may be higher or lower than the reading.'''
 ==Installing a modified kernel==
-Overclocking and undervolting require installation of a custom kernel.
-There are two types of kernels:
-===Kernel-Power (recommended)===
-[[Kernel_Power|kernel-power]], developed by Titan and maintained by Pali.
-They are compatible with [[Maemo 5/PR1.2|PR1.2]] and [[Maemo 5/PR1.3|PR1.3]], contain lots of additional features (IPv6, NAT etc) and bugfixes. In addition, they include a large set of possible frequencies (125 MHz-1.15 GHz) which can be manually set and tested without flashing a new kernel.
-The defaults are set to the standard 250-600 MHz range.
-This guide recommends using kernel-power v50, which at the time of writing is available in the [[extras]] catalog. Newer, more experimental kernels may be available through [[extras-testing]] or [[extras-devel]].
+===Kernel-Power===
 ====Installing from the repositories====
 # Open the Application Manager
@@ Line 68: / Line 66: @@
 ===Lehto's Kernel and other legacy kernels===
-Modified [[Maemo 5/PR1.1|PR1.1]] kernels by Lehto and others. The only difference from the stock Nokia kernel is the change of the available hardcoded frequencies.
 ====Flashing from X Terminal====
 * do a backup, have a PC nearby and know you are able to flash the N900 with flasher-3.5 - just in case
-# Launch X Terminal, then type<pre>sudo gainroot</pre>
+# Launch xterminal app then type sudo gainroot (need rootsh installed)
 # Type:<pre>softupd -vv -s --local</pre>(that is a double v)
 # Open new terminal
@@ Line 130: / Line 128: @@
 ===Manual Undervolting (Legacy)===
+====Undervolting and voltage tables====
 See: http://talk.maemo.org/showpost.php?p=628839&postcount=81
@@ Line 139: / Line 140: @@
 <pre>CPU dynamic power consumption = capacitance * frequency * voltage^2</pre>
-As can be seen from the formula, lower voltage plays greater part in CPU consumption than frequency. By reducing the voltage the damage of overclocking can be reduced and the battery life time extended. Alas, this claim only holds true for architectures not regulating the real voltage and current in special on chip regulators, like OMAP is known to do for almost every gate in their CPU and other SoC function blocks. TI calls this feature SmartReflex™ and lowering the voltage applied to the whole SoC, like suggested here, only reduces the voltage drop across these regulators, thus no positive effect on [[:wikipedia:Electromigration|electromigration damage]] caused by overclocking is to be expected.
+As can be seen from the formula, lower voltage plays greater part in CPU consumption than frequency. By reducing the voltage the damage of overclocking can be reduced and the battery life time extended. Alas, this claim only holds true for architectures not regulating the real voltage and current in special on chip regulators, like OMAP is known to do for almost every gate in their CPU and other SoC function blocks. TI calls this feature SmartReflex™ and lowering the voltage applied to the whole SoC, like suggested here, only reduces the voltage drop across these regulators, thus no positive effect on electromigration damage ([[:wikipedia:Electromigration]]) caused by overclocking is to be expected.
-====Calculating Voltages====
+====Calculating voltages====
-According to [http://talk.maemo.org/showpost.php?p=606031&postcount=2375 these calculations], the voltage can be varied in steps of 0.0125 V with values 0-72.
+According to [http://talk.maemo.org/showpost.php?p=606031&postcount=2375 this calculations] the voltage can be varied in steps of 0.0125 V with values 0-72. The formula is (with x being the kernel parameter value):
-The formula is (with x being the kernel parameter value):
-<pre>V = x * 0.0125 + 0.6</pre>
+<code>V = x * 0.0125 + 0.6</code>
 Examples:
@@ Line 153: / Line 154: @@
   Random voltage (x = 38):  38 * 0.0125 + 0.6 = 0.475 + 0.6 = 1.075 V
-====Voltage Table====
+=====Voltage Step Tables=====
-* V²/us for frequencies 720 and 805 need to be recalculated.
-* Bolded steps indicate the first frequency in the kernel which needs overvoltage. ''All frequencies after it are overvolted''.
+ FREQUENCY   Nokia   LV    ULV   XLV   ideal   starving
-{|
+MHz       30      30    25    30    30      22
-! Frequency !! Nokia !! LV !! ULV !! XLV !! ideal !! starving
+MHz     30      30    25    20    30      22
-|-
+MHz     38      38    25    30    30      28
-|0 MHz || 30 || 30 || 25 || 30 || 30 || 22
+MHz     48      48    33    33    30      29
-|-
+MHz    *54*     48    38    38    33      32
-| || 0.975V, 0.000 V²/us || 0.975V, 0.000 V²/us || 0.912V, 0.000 V²/us || 0.975V, 0.000 V²/us || 0.975V, 0.000 V²/us ||
+MHz     60     *54*   38    38    38      34
-|-
+MHz             54    45    45    45      41
-|125 MHz || 30 || 30 || 25 || 20 || 30 || 22
+MHz             54    45    45    45      42
-|-
+MHz             54    48    48    48      45
-| || 0.975V, 288.906 V²/us || 0.975V, 118.828 V²/us || 0.912V, 103.968 V²/us || 0.975V, 118.828 V²/us || 0.975V, 118.828 V²/us ||
+MHz             54    48    48    48      46
-|-
+MHz             54   *54*  *54*  *54*     49
-|250 MHz || 38 || 38 || 25 || 30 || 30 || 28
+MHz             54    54    54    54      52
-|-
+MHz            60    60    60    60      55
-| || 1.075 V, 118.828 V²/us || 1.075 V, 118.828 V²/us || 0.912V, 207.936 V²/us || 0.975V, 237.656 V²/us || 0.975V, 237.656 V²/us ||
+MHz            72    72    72    72      63
-|-
+MHz            72    72    72    72      69
-|500 MHz || 48 || 48 || 33  || 33 || 30 || 29
-|-
+Note: Asterisks indicate the first frequency in the kernel which needs overvoltage.
-| || 1.200 V, 720.000 V²/us || 1.200 V, 720.000 V²/us || 1.012V, 512.072 V²/us || 1.012V, 512.072 V²/us || 0.975V, 475.312 V²/us ||
-|-
+=====Actual Voltage Tables=====
-|550 MHz || '''54''' || 48 || 38 || 38 || 33 || 32
-|-
+======Nokia's kernel======
-| || 1.275 V, 894.094 V²/us || 1.200 V, 792.000 V²/us || 1.075V, 635.594 V²/us || 1.075V, 635.594 V²/us || 1.012V, 563.279 V²/us ||
-|-
+ VALUE  VOLTAGE   FREQUENCY     DYNAMIC POWER
-|600 MHz || 60 || '''54''' || 38 || 38 || 38 || 34
+     0.975 V   0 MHz         0.000 V²/us
-|-
+     0.975 V   125 MHz       118.828 V²/us
-| || 1.350 V, 1093.500 V²/us || 1.275 V, 975.375 V²/us || 1.075V, 693.375 V²/us || 1.075V, 693.375 V²/us || 1.075V, 693.375 V²/us ||
+     1.075 V   250 MHz       288.906 V²/us
-|-
+     1.200 V   500 MHz       720.000 V²/us
-|720 MHz || || 54 || 45 || 45 || 45 || 42
+     1.275 V   550 MHz       894.094 V²/us
-|-
+     1.350 V   600 MHz       1093.500 V²/us
-| || || 1.275 V, 1137.938 V²/us || 1.163 V, 1014.427 V²/us || 1.163 V, 1014.427 V²/us || 1.163 V, 1014.427 V²/us ||
-|-
+======kernel-power LV profile======
-|805 MHz || || 54 || 48 || 48 || 48 || 45
-|-
+ VALUE  VOLTAGE   FREQUENCY     DYNAMIC POWER
-| || || 1.275 V, 1316.756 V²/us || 1.200 V, 1166.400 V²/us || 1.200 V, 1166.400 V²/us || 1.200V, 1166.200 V²/us ||
+     0.975V    0 MHz         0.000 V²/us
-|-
+     0.975V    125 MHz       118.828 V²/us
-|850 MHz || || 54 || 48 || 48 || 48 || 46
+     1.075V    250 MHz       288.906 V²/us
-|-
+     1.200V    500 MHz       720.000 V²/us
-| || || 1.275 V, 1381.781 V²/us || 1.200 V, 1224.000 V²/us || 1.200 V, 1224.000 V²/us || 1.200V, 1224.000 V²/us ||
+     1.200V    550 MHz       792.000 V²/us
-|-
+     1.275V    600 MHz       975.375 V²/us
-|900 MHz || || 54 || '''54''' || '''54''' || '''54''' || 49
+     1.275V    700 MHz       1137.938 V²/us
-|-
+     1.275V    750 MHz       1219.219 V²/us
-| || || 1.275 V, 1463.062 V²/us || 1.275V, 1463.062 V²/us || 1.275V, 1463.062 V²/us || 1.275 V, 1463.062 V²/us ||
+     1.275V    810 MHz       1316.756 V²/us
-|-
+     1.275V    850 MHz       1381.781 V²/us
-|950 MHz || || 54 || 54 || 54 || 54 || 52
+     1.275V    900 MHz       1463.062 V²/us
-|-
+     1.275V    950 MHz       1544.344 V²/us
-| || || 1.275 V, 1544.344 V²/us || 1.275 V, 1544.344 V²/us || 1.275 V, 1544.344 V²/us || 1.275 V, 1544.344 V²/us ||
+     1.350V    1000 MHz      1822.500 V²/us
-|-
+     1.500V    1100 MHz      2475.000 V²/us
-|1000 MHz || || 60 || 60 || 60 || 60 || 55
+     1.500V    1200 MHz      2700.000 V²/us
-|-
-| || || 1.350 V, 1822.500 V²/us || 1.350 V, 1822.500 V²/us || 1.350 V, 1822.500 V²/us || 1.350 V, 1822.500 V²/us ||
+======kernel-power ULV profile======
-|-
-|1100 MHz || || 72 || 72 || 72 || 72 || 63
+ VALUE  VOLTAGE   FREQUENCY    DYNAMIC POWER
-|-
+     0.912V    0 MHz        0.000 V²/us
-| || || 1.500 V, 2475.000 V²/us || 1.500 V, 2475.000 V²/us || 1.500 V, 2475.000 V²/us || 1.500 V, 2475.000 V²/us ||
+     0.912V    125 MHz      103.968 V²/us
-|-
+     0.912V    250 MHz      207.936 V²/us
-|1150 MHz || || 72 || 72 || 72 || 72 || 69
+     1.012V    500 MHz      512.072 V²/us
-|-
+     1.075V    550 MHz      635.594 V²/us
-| || || 1.500 V, 2700.000 V²/us || 1.500 V, 2700.000 V²/us || 1.500 V, 2700.000 V²/us || 1.500 V, 2700.000 V²/us ||
+     1.075V    600 MHz      693.375 V²/us
-|}
+     1.163V    700 MHz      946.798 V²/us
+     1.163V    750 MHz      1014.427 V²/us
+     1.200V    810 MHz      1166.400 V²/us
+     1.200V    850 MHz      1224.000 V²/us
+     1.275V    900 MHz      1463.062 V²/us
+    1.275V    950 MHz      1544.344 V²/us
+     1.350V    1000 MHz     1822.500 V²/us
+     1.500V    1100 MHz     2475.000 V²/us
+     1.500V    1200 MHz     2700.000 V²/us
+======kernel-power XLV profile======
+ VALUE  VOLTAGE   FREQUENCY    DYNAMIC POWER
+     0.975V    0 MHz        0.000 V²/us
+     0.850V    125 MHz      90.312 V²/us
+     0.975V    250 MHz      237.656 V²/us
+     1.012V    500 MHz      512.072 V²/us
+     1.075V    550 MHz      635.594 V²/us
+     1.075V    600 MHz      693.375 V²/us
+     1.163V    700 MHz      946.798 V²/us
+     1.163V    750 MHz      1014.427 V²/us
+     1.200V    810 MHz      1166.400 V²/us
+     1.200V    850 MHz      1224.000 V²/us
+    1.275V    900 MHz      1463.062 V²/us
+     1.275V    950 MHz      1544.344 V²/us
+     1.350V    1000 MHz     1822.500 V²/us
+     1.500V    1100 MHz     2475.000 V²/us
+     1.500V    1150 MHz     2587.500 V²/us
+======kernel-power "ideal" profile======
+ VALUE  VOLTAGE   FREQUENCY    DYNAMIC POWER
+     0.975V    0 MHz        0.000 V²/us
+     0.975V    125 MHz      118.828 V²/us
+     0.975V    250 MHz      237.656 V²/us
+     0.975V    500 MHz      475.312 V²/us
+     1.012V    550 MHz      563.279 V²/us
+     1.075V    600 MHz      693.375 V²/us
+     1.163V    700 MHz      946.798 V²/us
+     1.163V    750 MHz      1014.427 V²/us
+     1.200V    810 MHz      1166.400 V²/us
+     1.200V    850 MHz      1224.000 V²/us
+     1.275V    900 MHz      1463.062 V²/us
+     1.275V    950 MHz      1544.344 V²/us
+     1.350V    1000 MHz     1822.500 V²/us
+     1.500V    1100 MHz     2475.000 V²/us
+     1.500V    1150 MHz     2587.500 V²/us
 ==Useful scripts==