125/1000 cpu freqs
 

I need some advices about overclocking the n900 . With 125/1000 mhz I feel a little lag sometimes , should I increase voltages ? Also , these frequencies are safe ? I don't want to damage the cpu permanently .

Here is the default preset I'm using now .

# DO NOT EDIT THIS FILE - CREATE A COPY OF IT FOR CUSTOMIZATION
# minimum frequency to use
MINFREQ=125
# maximum frequency to use
MAXFREQ=1000
# list of frequency configurations: each "frequency:volt,dsprate"
FREQS="0:20,90 125:25,90 250:38,180 500:30,360 550:54,400 600:60,430 700:60,430 750:60,430 805:60,430 850:60,500 900:60,500 950:60,500 1000:60,500 1100:72,520 1150:72,520"
SMARTREFLEX_VDD1=0
SMARTREFLEX_VDD2=0
GOVERNOR=ondemand
UP_THRESHOLD=95
SAMPLING_RATE=300000
IGNORE_NICE_LOAD=0
POWERSAVE_BIAS=0

Re: 125/1000 cpu freqs
 

No, voltage will have no effect on the speed on the phone. If you still find it lagging after OC'ing, try swappolube and/or custom transition settings.

Re: 125/1000 cpu freqs
 

You can also, if you feel you must, increase the minimum frequency. IF the lag you're experiencing is CPU-bound (i.e. it's because the CPU can't handle something fast enough, not, say, because of SWAP and disk I/O bottlenecks).

Ideally it should still "sleep" at 0mhz when completely unused. The thing is the on-demand governor for the CPU only increases CPU frequency when it's pretty intensely used. So if the current frequency is 125 Mhz, it's not gonna go up tp 250MHz or whatever, until the CPU is 90% busy, or something like that. From there it's not going to go up higher unless CPU is still 90% busy, etc.

Re: 125/1000 cpu freqs
 

Might be more responsive at 500 to 1000 MHz.

Re: 125/1000 cpu freqs
 

Now I put UP_THRESHOLD 75 instead 95 . What about safety with these freqs ?

Re: 125/1000 cpu freqs
 

Yep, up_threshold at 75 should help a bit, at least in some usecases.

Safety... is hard with CPU overclocking.

I'm not an expert, but I'd say, for the time being, unless you're getting spontaneous reboots, you should be okay. Long long term, you might get unlucky and your CPU may wear down because of the overclock - but that's entirely a matter of luck - your CPU may be fine right now and forever at those frequencies, or it may be fine now but develop some fault a year from now. *Shrug* I honestly have no clue.

Re: 125/1000 cpu freqs
 

AND there's the overhead of having to switch among 13 different levels. You could fix it by removing some of the allowed frequencies, like this:

#COPY FOR CUSTOMIZATION:
# minimum frequency to use
MINFREQ=125
# maximum frequency to use
MAXFREQ=1000
# list of frequency configurations: each "frequency:volt,dsprate"
FREQS="0:20,90 125:25,90 250:36,180 500:38,360 750:60,430 1000:60,500"
SMARTREFLEX_VDD1=0
SMARTREFLEX_VDD2=0
GOVERNOR=ondemand
UP_THRESHOLD=75
SAMPLING_RATE=300000
IGNORE_NICE_LOAD=0
POWERSAVE_BIAS=0

Also, putting it straight to 125 is a waste of energy IMO... And in case of reboots, allowing bigger voltages use to be a fix.

Re: 125/1000 cpu freqs
 

I let only 4 levels

FREQS="0:20,90 125:25,90 500:38,360 1000:60,500"

By the way , when the freq goes to 0 ? When the device is locked ?

Re: 125/1000 cpu freqs
 

Do a thread search on the overclocking thread. There were lots of tests, and it came out that the peek efficiency was actually at 500Mhz. That's why most profiles set that as a default.

Tweaking the number of levels, and the speed to change between them, may help if it's the speed of the initial response you care about. If it's general lag though, you may want to look more at what's running system wide.

Re: 125/1000 cpu freqs
 

i am using 250-500-750-1000, the rest of the speeds are unnecessary because when you reach 500 and it thinks it needs 600, but by the time it changes to 600, 600 hits 95% load and it looks for 700 or higher.

only jumping 4 steps, usually stays at 250/500 when no load

and hovers at 750/1000 when browing or running some other tasks

if you are a heavy user who always uses the device, never letting it rest till the battery is flat, then you might want to consider 500-750-1000 or just 500-1000, the device will be much more responsive.

there are also some people who run the device only at 1000 all the time, but i would not recommend this. there might be *some long term effects (* some are running it for months without issues so far)

and as someone pointed out earlier, 125 is useless because somehow it will always go to 250 the moment you unlock. in simpler terms, 125 is just too slow to do anything useful.

also SAMPLING_RATE=300000 means when you launch something, when it realizes it needs to switch to a higher speed, it will need to wait for 300000 before switching = short delay before it goes smoother

but changing SAMPLING_RATE=150000 means it is not only faster to switch to a faster speed when needed also switches back to slower clock faster = immediate speed when it needs it.

and i dont think jump from 500mhz to 550mhz (500:30,360 550:54,400 ) requires such a big jump in voltage from 30 to 54.

Re: 125/1000 cpu freqs
 

0,250,500,1000 is better than 0,125,500,1000

and yes, n900 sleeps at 0

Re: 125/1000 cpu freqs
 

Ok , now I'm using this . :)

FREQS="0:20,90 250:30 500:38,360 1000:60,500"
UP_THRESHOLD=75
SAMPLING_RATE=150000

Voltages are good ?

Re: 125/1000 cpu freqs
 

overclocking _will_ shorten the lifetime of your device - probably dramatically

Re: 125/1000 cpu freqs
 

yup, voltages are normal now.

each device has a processor with different yields, you might be able to go lower, but you have to experiment.

if the voltage too low, it will just restart and you have to change the voltage again and try.

mine is 0:25, 250:25, 500:35, 1000:60

some people go much much lower.

you can create copies of the included profiles and modify them further. those are lv, ulv, xlv and ideal

but do remember what you modify so that you know what caused the device to freeze and adjust that value. so always keep a reference copy once you reach a stable voltage.

most importantly, change one value at a time and test it, or else you wont know which value caused the freezing/rebooting.

ideal methods to test would be to play a media file while online using wifi and loading some video from youtube for e.g. - use your imagination.

install conky as well to see what is the processor doing when running tasks in the background

htop also is a good application to monitor running daemons and apps but conky is more graphical and shows more information at a glance

try this first,

0:20, 250:30, 500:38, 1000:56

if it is stable at that for a day, running multiple tasks, try this

0:20, 250:30, 500:38, 1000:52

if it crashes at 52 try 54

you get the idea

and then once you find a stable voltage for 1000 for e.g. 56, then adjust the voltage for 500, for e.g. 34

0:20, 250:30, 500:34, 1000:56

its a very logical method to find all the lowest voltages for each frequency.

and remember, stability is more important than lowest possible voltage, because if its unstable and reboots - you know how much battery rebooting process eats ???

Re: 125/1000 cpu freqs
 

Won't decreasing sampling time increase overhead just like increasing the amount of different frequencies available increases overhead?

Re: 125/1000 cpu freqs
 

@jananan - thanks for advices mate , I am familiar with overclocking because I used to overclock my pc a lot , I spent a lot of time finding good voltages and other parameters . :D I will try some tweaks tomorrow . :)

Re: 125/1000 cpu freqs
 

I am permanently running at 1000 min max lv with 0 issues.

going beyond that = 1150 min max lv will cause random reboots in watching videos, playing webos games, watching streaming videos... but very erratic. sometimes it's ok for a day or two but sometimes, it just doesn't accept it... but it's ULTRA smooth at 1150.

1000 min max is already very smooth honestly. try it

Re: 125/1000 cpu freqs
 

Nobody should be using a minimum frequency of 125MHz.
Stock N900 uses 250 min 600 max.
If you use 125MHz minimum frequency, it may lag.
This was also noted out by Titan. (maker of power kernel)

Re: 125/1000 cpu freqs
 

I'm running 0-500-600-750 XLV up_th=75, rate 300000.
Everything is so much smoother now.

Oddly, all apps run fine on XLV, while videos just don't play, and I need to load default to play videos. Is this the result of extreme undervolting?

Re: 125/1000 cpu freqs
 

Yes , I tried overclocking on XLV too and it crashes on some apps . By the way , what battery life you have with these settings ?

Re: 125/1000 cpu freqs
 

From a full charge to zero doing nothing (2G):
~2 3/4 days.

From a full charge to zero with heavy use (browsing while using Easy Debian, sharing files over the network, 2G, WiFi Maximum Power Saving): Short of 8 hours.

Re: 125/1000 cpu freqs
 

you have a point there, it will switch back and forth too often between different clock speeds when the sampling time is lowered, for e.g. to 100000

but 150000 seems to be the sweet spot as i notice slight lag when apps are launched using 300000 sampling time as it staggers for a little while at the lower freq before jumping to the next highest.

its buttery smooth at 150000, but it does jump back and forth unnecessarily at times.

Re: 125/1000 cpu freqs
 

with CSSU and kernel power 47 battery seems to last longer while idle, i am not sure if you are on a similar configuration.

Re: 125/1000 cpu freqs
 

try the next one with slightly higher voltages, ulv if i am not mistaken. ulv works fine for most batches of n900.

Re: 125/1000 cpu freqs
 

Right now I am using FREQS="0:20,90 250:25,180 500:33,360 1000:60,500" (ULV preset)

I've open pidgin (online) + angry birds rio + angry birds seasons + wifieye with autorefresh + other 16 random applications and all these while playing a video wich was very very smooth , just like only the media player was open . :D:D:D This phone is actually any-other-phone-killer .

Re: 125/1000 cpu freqs
 

looks like you've hit the jackpot.

now try reducing the voltage for 1000:60,500, maybe 58 and try for a day or two, to be sure its really stable in all situations

then try 56 and so on...

that will give you more runtime when you are actively using it because your phone will be at 1000mhz most of the time now unless its locked or some simple app is run.

when you are actively using it will be at 1000mhz 97% of the time and 500mhz 3% of the time maybe.

try the same settings but 1100:60,500 instead of 1000 see if it stays stable.

if it does, you have a winner !!

Re: 125/1000 cpu freqs
 

I am on CSSU and power47.
I guess the N900 really sucks up the juice hard on the puny BL-5J.

Re: 125/1000 cpu freqs
 

I tried 1000:58,500 , it played a movie file very well but I got a random reboot when I open the KMplayer , is this a bug or it's because of the overclock ?

Re: 125/1000 cpu freqs
 

Most likely due to overclock

Re: 125/1000 cpu freqs
 

What is actually IGNORE_NICE_LOADS ?

Re: 125/1000 cpu freqs
 

I got a problem , at 250/1000 freqs when I play a video sometimes it gets stuck and I have to close the media player , so I thought the voltage on 500 mhz freq it's too low and I made limits 250/500 to test these two freqs . While playing several videos I had putty open in background and waiting the video to crash , when it crashed I used "awk '{print $1/1000" MHz"}' /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq" command and I got 550Mhz and it got stuck at this frequency till I open again mediaplayer . What actually makes the frequency jump over the limit ? :-/

Re: 125/1000 cpu freqs
 

What's that IGNORE_NICE_LOAD ? I wanna know if worths enabling it or not . :-s

Re: 125/1000 cpu freqs
 

It does exactly what it says it does - ignore nice load. Basically, if you leave that on 0, all processes count towards the up_threshold. If you set that to 1, renice'd processes don't count towards the up_threshold (can be bad or good depending on which app is misbehaving this time :P )

Leave it on 0.

EDIT: Saw the first post. Increase your voltages, simplify the steps. 125-1000 isn't recommended, try to do 250-1000 probably with steps in 250-500-750-1000, whatever voltage your phone needs, and if possible, SR on.

Re: 125/1000 cpu freqs
 

Now I'm using 0:20,90 250:25,180 500:30,360 1000:60,500 . I don't think SR would work at 1000 , I know it works only with max freq 805 mhz .

Re: 125/1000 cpu freqs
 

VDD2 SR works, try to enable it...
I don't know if it makes much difference, but yeah...

Re: 125/1000 cpu freqs
 

Ok , I enabled VDD2 SR . What actually is this Smart Reflex ? what is doing ?

Sorry for many questions , I am pretty noob and this phone is making me curious everyday , that's why I love it . :D

Re: 125/1000 cpu freqs
 

It turns off parts of the chip not in use + automatically lowers the voltage for parts that don't need too much. I've got VDD1 and VDD2 SR enabled, and I don't overclock.

Re: 125/1000 cpu freqs
 

From my experience, enabling SmartReflex with core freq above 850Mhz instantly reboots the phone; at 805Mhz and below it works flawlessly; and at exactly 850Mhz it works, but I start to get artifacts on the screen and dmesg errors related to the graphics chip. I have a hunch that's because the DSP frequency goes up to 500Mhz at 850+, but is only at 430Mhz for 600-805 (and lower still for core freqs below that). I'm lucky with my N900 though (since it was replaced by Nokia Care) as its CPU is good enough to be stable whilst running the "drained" config, so of course YMMV.

Re: 125/1000 cpu freqs
 

Does the SR needs an increase in voltages ? Because it causes unexpected reboots with same freqs and voltages from other profile without SR .

stable profile : FREQS="0:20,90 125:20,90 250:25,180 500:30,360" , VDD1=0 VDD2=0
sr profile : FREQS="0:20,90 125:20,90 250:25,180 500:30,360" , VDD=1 VDD2=1

Where is the problem ?