How Do You Over / Under Clock On R198?

[louigi600]

It looks like things are done a little different in 2.4 kernel especially for the pxa270.

Shula: you're using that script on pre beta4 release ? .... /proc/cccr_change and /proc/driver/w100/fastsysclk do not exist on 2.6 kernel proc tree.

[louigi600]

I've found a way for the corgi family (but only for undeclocking)... but this has ot been tested very long so stability may be an issue (use at your own risk).

No script for it yet.

Code: [Select]

cd /sys/devices/system/cpu/cpu0/cpufreq
cat scaling_avalible_frequencies
#select now which frequency you want to run lets say 99532 kHz
echo 99532 > scaling_max_freq
#to put it back to normal echo 398131 > scaling_max_freqOn Cxx00 there are 2 governors avalible "performance and pxa27x_governor"
when pxa27x_governor is selected you get more frequencies avalible and you can also overclock ... but be carefull because on pxa270 you also need to adjust cpu-voltage accordingly.
If you look in the avalible governors on c7x0 you will notice that only one governor is avalible ... while on cxx00 there is 2.
So I guess that for the moment overclocking is not possible on c7x0 using pdaxrom r197 ... but you can undeclock if you like.

[shula]

It looks like things are done a little different in 2.4 kernel especially for the pxa270.

Shula: you're using that script on pre beta4 release ? .... /proc/cccr_change and /proc/driver/w100/fastsysclk do not exist on 2.6 kernel proc tree.
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sorry guys
i tested this script in this particular setting only:
pdax beta3 and lower
kernel 2.4.x of course
on my C860


my newly r197 doesn't work for these values and /dev/ .

[louigi600]

sorry guys
i tested this script in this particular setting only:
pdax beta3 and lower
kernel 2.4.x of course
on my C860

my newly r197 doesn't work for these values and /dev/ .

But you can still underclock like I showed above.

I had a talk with kernel developer about this and it turns out that overclock on pxa255 is possible but not implemented.

Some things that everyone should ponder about about overclocking:
Z case is plastic (not good heat conductor)
overclocking inevitably produces more heat
depending on a bunch of factors like ambient temp and how close to abslolute maximum temp rating Sharp implemented the Z it could turn out that overclocking for long periods with heavy cpu load may permanently damage the Z.

This may be one of the reasons why overclock has not been implemented for pxa255.

[ecc_hy]

As a handheld device, the powersaving always be the very important function.
We can use speedstep in dynamic, down cpu freq clock before the overheat, up it when cpu usage getting high.
The speedstep can hold my c1000 to listen songs or read a ebook over 6-12 hours in pdaxrom 1.1beta3 now.
No reason to give up it when moveing to kernel 2.6.