Poll: Do you think its possible to overclock the N900?!
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Do you think its possible to overclock the N900?!

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Posts: 992 | Thanked: 995 times | Joined on Dec 2009 @ California
#3271
Originally Posted by AlMehdi View Post
But wasn't the question how this affect an undervolted OC? I can not say i understand the matematic but shouldn't you try to compare the stock output with the OCd at different VSEL setting?

The stock takes 1.350V on 600mhz and when running 950mhz you could do it on 1.200V. The stock use far less volts on lower mhz which would explain the lesser energy consumption but the OCd use even less than stock.

So does the energy increase more if i am running 950mhz/1.200V comapred with the stock kernel? As the consumption is less i do not think so but i am not an expert on the subject.
The sole goal of overclocking - get a faster N900.

But this depends from multiple factors and if it could be found, for exam, that in proper handling CPU spends less energy with high frequency (just because it runs faster and energy increase is proportionally less) then some things become simpler. Don't forget, somebody can't overclock because CPU instability danger but they want a faster N900 too.

One example - switching between CPU frequencies takes time and frequent switching actually steals CPU performance. The CPU switching itself takes around 30nsec but it looks like some equipment needs to be put on sleep and restored during switch process. So, many frequencies may also steal your CPU performance.

But put all hopes on OC for N900 performance may be not very good, somebody (like me) hesitates OC especially with undervoltage because CPU may be unstable. At least a small research is needed to be sure that it wouldn't corrupt valuable N900 data.

However, the OC experiments are good - nightfire reports that he routinely runs N900 on 500MHz and has 24h-48h usage on moderate work. It is a good sign and it advised me to look into performance vs energy ratio with more attention. Based on my Intel X86 experience I didn't expect that CPU on high frequency may consume power in less proportion than CPU performance increase.

Last edited by egoshin; 2010-04-23 at 15:31.
 
Posts: 992 | Thanked: 995 times | Joined on Dec 2009 @ California
#3272
Originally Posted by Gusse View Post
CPU active settings:
...

CPU idle settings:
This is very interesting, it looks like you may have advantage because you minimize switching in idle periods! (only 2 frequencies and no chance to have something beyond 500MHz during idle periods. 125MHz actually is too small and ondemand cpufrequency governor switches to 500MHz each time then there is a load.)
 
Posts: 59 | Thanked: 7 times | Joined on Jan 2010
#3273
i use the latest power flasher 25 and when i try to enable lv settings(with the command /usr/sbin/kernel-load /usr/share/kernel-power-settings/lv) my frequency reset to 599 . (it is not the charger as i was previous think). how can i fix this ?
 
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Posts: 168 | Thanked: 206 times | Joined on Apr 2010 @ Finland
#3274
Originally Posted by egoshin View Post
This is very interesting, it looks like you may have advantage because you minimize switching in idle periods! (only 2 frequencies and no chance to have something beyond 500MHz during idle periods. 125MHz actually is too small and ondemand cpufrequency governor switches to 500MHz each time then there is a load.)
This was my intention for idle; to spend as much time at as low freq and when CPU is loaded it will change immediately to 500MHz, which is enough for any background app.

I tried also min. 250MHz, but when SW request CPU power, it jumped always to 500MHz (or to max freq). 250MHz as a maximum would be too low, I think. Therefore I decided to select 125MHz and 500MHz for idle. It is working very well.

Last edited by Gusse; 2010-04-23 at 16:47.
 
Posts: 1,751 | Thanked: 844 times | Joined on Feb 2010 @ Sweden
#3275
Originally Posted by suphiceto View Post
First of all, this is my first post in here and I have read most of this thread and I wan to thank everybody who provided all this information. And especially to people who are testing and producing all of this overclocking information.

I just got my N900 this week and I am very happy with it. First I overclocked with Letho's custom 125-900 kernel and It has been running with no problem. After reading about the power saving voltages of Titan's kernel, I decided to give it a try. So I reflashed to the stock kernel.Then I followed the Wiki with instructions, first I installed kernel-power settings and rootsh, then I checked with
uname -r
and returned with "2.6.28.10power-omap1" (so assuming that everything installed fine)

Then I did
sudo gainroot
to gain the control and then I entered
/usr/sbin/kernel-load /usr/share/kernel-power-settings/ideal
to flash the kernel, but it comes back and says ": not found".
Please guide me to right direction; I am new with linux commands and not sure what to do next. Thanks..
Maybe you missed to install the Enhanced kernel?

Try in the terminal as root:
Code:
apt-get install kernel-power-flasher kernel-power-settings
 
Posts: 992 | Thanked: 995 times | Joined on Dec 2009 @ California
#3276
Originally Posted by Gusse View Post
This was my intention for idle; to spend as much time at as low freq and when CPU is loaded it will change immediately to 500MHz, which is enough for any background app.
CPU in idle has (at least in theory) clocks switched OFF. However, it has VDD1/2 and it has power leakage too. If we set (somehow) the idle VDD1/2 to a minimum for any frequency we may not need lowfreq anymore (because it looks from my measurement that CPU in high freq may consume energy less per CPU cycle or same. However, SmartReflex should be switched on for that).
 
Posts: 451 | Thanked: 334 times | Joined on Sep 2009
#3277
Originally Posted by Gusse View Post
Create user -file in /etc/sudoers.d/ and add following to it.
Code:
user ALL = (ALL) NOPASSWD: ALL
root ALL = (ALL) NOPASSWD: ALL
and run update-sudoers -command.
Don't do this!!!

You can get seriously messed up. The N900 runs all processes as user, and this way any script etc on your phone can completely destroy your system.

Rather, create the file /etc/sudoers.d/kernel-load.sh with this text:
Code:
user ALL = NOPASSWD: /usr/sbin/kernel-load
and then run
Code:
# update-sudoers
 

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Posts: 844 | Thanked: 521 times | Joined on Jan 2009 @ UK southampton
#3278
Originally Posted by 白い熊 View Post
Don't do this!!!

You can get seriously messed up. The N900 runs all processes as user, and this way any script etc on your phone can completely destroy your system.

Rather, create the file /etc/sudoers.d/kernel-load.sh with this text:
Code:
user ALL = NOPASSWD: /usr/sbin/kernel-load
and then run
Code:
# update-sudoers
VERY VERY good advice. Don't update sudoers if you are not very sure of what your doing.
 

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Posts: 126 | Thanked: 327 times | Joined on Nov 2009 @ Finland
#3279
Im still running 1150mhz. No fried device yet!
__________________
My OC kernel collection
 
Posts: 451 | Thanked: 334 times | Joined on Sep 2009
#3280
Originally Posted by Lehto View Post
Im still running 1150mhz. No fried device yet!
I tried too, but the battery drain I experienced was phenomenal. Left the phone in standby overnight, half the charge gone...
 
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