When I first switched to CM9 a month ago or so, I noticed that the undervolt was SO limited compared to CM7 (well, stock kernels don't support undervolting, but the result is the same with different kernels).
Under CM7 I could undervolt at -250mV (100mhz frequency step) and at -75mV for every step between 200 and 1000mhz.
Now I can undervolt at -25mV between 200mhz and 1000mhz and no undervolt is possible at 100mhz. Anything lower than -25mV will cause instant or delayed freezes and reboots.
If the hardware is still the same, I wonder if there's an explaination for such behaviour.
ICS/JB architectures put way more stress on CPU/GPU/RAM then FROYO/GB thus causing less OC/UV.
flapane said:
Under CM7 I could undervolt at -250mV (100mhz frequency step) and at -75mV for every step between 200 and 1000mhz.
Now I can undervolt at -25mV between 200mhz and 1000mhz and no undervolt is possible at 100mhz. Anything lower than -25mV will cause instant or delayed freezes and reboots.
Click to expand...
Click to collapse
That's interesting.
After a couple of months, I can say that those voltages keep the CPU rock solid under CM10 and Semaphore kernel:
-25mv @ 800 and 1000mhz
-75mv @ 100, 200mhz and 400mhz
It's worse than CM7, but it's better than CM9.
Somehow, JB architecture has been improved.
Related
Yesterday I thought I would test my battery life if I left my clock speed at 806 MHz, It lasted over 24 hours with no real speed decrease... I am requesting that a developer makes a kernel that is underclocked to 806 MHz and undervolted as much as possible so we can see how much battery life we can pull out of this thing.
take intersectRavens 800mv (or 925) kernel and underclock via setcpu?
lower than 800mv won't be possible, even 800mv is too low for me, it uses more battery cause data connections is very unstable. 925 gives better battery life for me.
IR kernel supports conservative governor too.. works great for me.
yeah just use set cpu to underclock the device. all these kernels already have the lowest voltages for each cpu frequency. but once again, the lower the voltage, the lower your signal strength, and if you signal strength gets too low, your phone will boost voltage to the radio to try to increase it and it will end up using more power. this is why many prefer the 925mv kernels as opposed to the 800mv ones.
this is my understanding, please correct me if i am wrong.
nellyspageli said:
yeah just use set cpu to underclock the device. all these kernels already have the lowest voltages for each cpu frequency. but once again, the lower the voltage, the lower your signal strength, and if you signal strength gets too low, your phone will boost voltage to the radio to try to increase it and it will end up using more power. this is why many prefer the 925mv kernels as opposed to the 800mv ones.
this is my understanding, please correct me if i am wrong.
Click to expand...
Click to collapse
I wasn't sure, that's why I said lowest possible. So I think I'll just do that, but from what you said I'm now wondering if we can OV the radio's voltage from the kernel to fix the 3g/speed problems...
will it work on froyo? i have CM6alpha1
link to the kernal to use and setCPU settings please (including profiles) much appreciated!
i'm using SetCPU:
governor: conservative
freq range: 200-1,200 mhz
undervolted
have tried various kernels (ninphetamine, speedmod, ragemod - current, mirage) and roms (cognition, solarflare, and leomar -current)
one thing in common is that it in doesn't keep the freq at the minimum for a longer period. even after an 8 hour idle time at night, my phone's at 30% on the 200 mhz, and at about 35% at the 800 mhz.
anyone with the same problem?
i'm using only the setCPU widget and no other downloaded/installed apk's which run in the background (i.e. ATK, etc)
The phone will clock up as and when required, this is normal, it won't stick to the lowest unless you clamp the scaling down, also the phone will clock up on touch inputs to keep things smooth.
Sent from my GT-I9100 using xda premium
thanks!
+1
poch_1421 said:
i'm using SetCPU:
governor: conservative
freq range: 200-1,200 mhz
undervolted
have tried various kernels (ninphetamine, speedmod, ragemod - current, mirage) and roms (cognition, solarflare, and leomar -current)
one thing in common is that it in doesn't keep the freq at the minimum for a longer period. even after an 8 hour idle time at night, my phone's at 30% on the 200 mhz, and at about 35% at the 800 mhz.
anyone with the same problem?
i'm using only the setCPU widget and no other downloaded/installed apk's which run in the background (i.e. ATK, etc)
Click to expand...
Click to collapse
Aren't you using a Screen Off profile...? A powersave bias value could also help
Just to let you know ahead of time, I know how to overclock & undervolt
My question:
Should I notice better battery life with 1400MHz @ 1275mV or 1200MHz @ 1275mV?
Even more basic - "With my voltages the same, but clocks higher, will I notice less battery life?"
My thoughts:
Not using more mV than a stock 1200MHz, so I shouldn't notice anymore drain
Should be finishing tasks faster - Saving Battery Life
So I shouldn't be noticing any more drain then stock, but it is faster.I do notice a difference in speed between 1200 & 1400MHz, otherwise I would just use 1200MHz @ my current stable of 1200mV.
Overclocking/Undervolting
You might want to grab SetCPU or Pimp My CPU from the market and memorize some different CPU profiles that would allow you to test and see the results of what you want to do.
Alright so I've been tweaking my cpu using setcpu. So far I've been forcing it to run on each stepping while i drop the voltage 25mV at a time. I've got both the 200 and 500 running at 850mV no problem. The problem occurred when after i set my 800Hz stepping 850 mV and then returned my min back to 200mhz. It locks up every time. 800mhz runs fine on its own @850mV but not with other steppings. I've been told before that big jumps in voltage between steppings can lead to instability but i have all three at 850mV. I was just wondering if anyone m ew why. Also if i force it to run only one frequency will it still go into deep sleep? Thanks
I don't know if this is tandard on all kernels but on my kernel for example the steps are like that:
1000mhz=1175mv
1100mhz=1225mv
1200mhz=1275mv
Now at THIS point it starts getting weird. Suddenly the voltage increases by 25mv each
1300mhz=1300mv
1400mhz=1325mv
then it's 50 again
1500mhz=1375mv
then 25 again
1600mhz=1400mv
I know a bit about overclocking and overvolting CPUs. And I know that the higher you go the bigger the steps to increase voltage have to be (assuming you always choose the lowest voltage possible on which everything is stable). That's just due to physics. And now the opposite is the case... Why is the step from 1,5ghz to 1,6ghz only 25mv but from 1000 to 1100mhz it's 50mv? This doesn't make much sense.
Seriously no wonder that my phone is instable on 1600mhz. I guess the voltage just isn't high enought so the transistors aren't able to do their job properly within that short amount of time they're given at 1,6ghz.
Are the voltage steps like that on every kernel?
Frozenthunder said:
I don't know if this is tandard on all kernels but on my kernel for example the steps are like that:
1000mhz=1175mv
1100mhz=1225mv
1200mhz=1275mv
Now at THIS point it starts getting weird. Suddenly the voltage increases by 25mv each
1300mhz=1300mv
1400mhz=1325mv
then it's 50 again
1500mhz=1375mv
then 25 again
1600mhz=1400mv
I know a bit about overclocking and overvolting CPUs. And I know that the higher you go the bigger the steps to increase voltage have to be (assuming you always choose the lowest voltage possible on which everything is stable). That's just due to physics. And now the opposite is the case... Why is the step from 1,5ghz to 1,6ghz only 25mv but from 1000 to 1100mhz it's 50mv? This doesn't make much sense.
Seriously no wonder that my phone is instable on 1600mhz. I guess the voltage just isn't high enought so the transistors aren't able to do their job properly within that short amount of time they're given at 1,6ghz.
Are the voltage steps like that on every kernel?
Click to expand...
Click to collapse
I'm on Siyah 2.6.14 Voltage Control setting as follow:
I/O = bfq & Governor = ondemand
1600Mhz - 1500mv
1400Mhz - 1300mv
1200Mhz - 1200mv
1000Mhz - 1100mv
800Mhz - 1000mv
500Mhz - 950mv
200Mhz - 900mv
100Mhz - 900mv
I've applied these setting as default at bootup with no problem.
OC to 1600Mhz + set to Performance gives me 6800-6990 benchmark score in Antutu.
Which kernel are you on?
Siyah 3.2
I see you are using 1,5V on 1,6ghz. Maybe that's why you running stable?
When I set max clock to 1,6ghz and 1,4V at that clock then I get random app crashes/freezes... Once I tried shutting down my phone and it made some very loud and creepy noise... Some very loud beeping. It was definitely not the shutdown sound of the rom.
On my stock rom I just get random reboot.
Can you also permanently work on 1,[email protected],5V (setting min clock to 1,6ghz) without freezes/crashes?
Also funny that at 1400mhz you are on 1,3v while standard on siyah 3.2 is [email protected],4ghz
While 1600mhz is lower voltage again.. This is messed up
Frozenthunder said:
Siyah 3.2
I see you are using 1,5V on 1,6ghz. Maybe that's why you running stable?
When I set max clock to 1,6ghz and 1,4V at that clock then I get random app crashes/freezes... Once I tried shutting down my phone and it made some very loud and creepy noise... Some very loud beeping. It was definitely not the shutdown sound of the rom.
On my stock rom I just get random reboot.
Can you also permanently work on 1,[email protected],5V (setting min clock to 1,6ghz) without freezes/crashes?
Also funny that at 1400mhz you are on 1,3v while standard on siyah 3.2 is [email protected],4ghz
While 1600mhz is lower voltage again.. This is messed up
Click to expand...
Click to collapse
I face lots of apps crashed/Forced closed before someone refer me to here:
http://forum.xda-developers.com/showthread.php?t=1466017
Take a look....
i neva do oc , but had tried ov an phone simply was not stable as out of the box.as my sig says iam good wiv 520 apps right now wiv decent batt life and good speed,only thing u got to kno wat ur phone can handle..