Low voltage cutoff - AT&T Samsung Galaxy S II SGH-I777

Just curious, does anyone know what the low voltage threshold is for our phone? Meaning the voltage at which the device will power itself off.

twiggums said:
Just curious, does anyone know what the low voltage threshold is for our phone? Meaning the voltage at which the device will power itself off.
Click to expand...
Click to collapse
Depends on the device.
http://forum.xda-developers.com/showpost.php?p=21348831&postcount=730

Simba501 said:
Depends on the device.
http://forum.xda-developers.com/showpost.php?p=21348831&postcount=730
Click to expand...
Click to collapse
Read through the page linked and it appears to be in ref to undervolting, I'm referring to battery voltage.

Related

What App to control cpu governor?

What App is everyone using to set their cpu governor along with voltage control? Tegrak? SetCPU?
Also, if you can run 100 mhz on your rom.. Is it even worth using?
Sent from my SCH-I500 using XDA App
Crap wrong section. Move please.
Sent from my SCH-I500 using XDA App
What kernel are you using? If on an OTB kernel, you can use voltage Control. Actually the newest version of voltage control can change governor for any kernel i think, though you can't change voltage settings.
elarson006 said:
What kernel are you using? If on an OTB kernel, you can use voltage Control. Actually the newest version of voltage control can change governor for any kernel i think, though you can't change voltage settings.
Click to expand...
Click to collapse
Otb
Sent from my SCH-I500 using XDA App
Looks like you can change voltages as well on this new version, thanks . Any ideas about the 100 mhz step?
Sent from my SCH-I500 using XDA App
Increasing the voltage for the most part increases the amount of power the CPU consumes (and amount of heat generated!). Higher clock speeds require more power, and therefore a higher voltage. As clock speeds decrease, it's safer to decrease the voltages.
The idea of the having all this control is to allow the user to customize how their phone operates. You can overclock it and go for performance all the way, or keep the clock speeds low so you can decrease voltage and save battery. If you want, you can create a mix between them by decreasing the voltage different amounts on each of the clock speed steps.
Voltage control does the clock voltage and governor for me. I can use 100mhz with CM7 but I wouldn't be too worried about not having it.
Keithn said:
Voltage control does the clock voltage and governor for me. I can use 100mhz with CM7 but I wouldn't be too worried about not having it.
Click to expand...
Click to collapse
Well the thing is i read that it's essentially worthless, as it draws the same voltage as the 200 mhz step... Hence why it's disabled by default
Sent from my SCH-I500 using XDA App
Putting the CPU all the way down to 100 MHz can cause some problems anyway, particularly if you use your phone to play music. A lot of software isn't designed to operate on clock speeds that low. I only go down to 200 MHz.
kallell said:
Well the thing is i read that it's essentially worthless, as it draws the same voltage as the 200 mhz step... Hence why it's disabled by default
Sent from my SCH-I500 using XDA App
Click to expand...
Click to collapse
Although you wouldn't notice the difference because it's so little, you will save more battery if you use 100mhz. Because it's on 100mhz you will be able to put it a lot lower than 200mhz. Many people including me is putting -150 with 100mhz.
deaffob said:
Although you wouldn't notice the difference because it's so little, you will save more battery if you use 100mhz. Because it's on 100mhz you will be able to put it a lot lower than 200mhz. Many people including me is putting -150 with 100mhz.
Click to expand...
Click to collapse
Problem for most undervolting that low at 100mhz would be running any music app while the screen is off then upon waking up your phone it would freeze up.

[Q] Max CPU temperature?

Anyone have a good estimate of what the max safe temperature for the armv6 cpu is? I have setCPU configured to throttle back at 46 degrees, but could that limit be safely set higher?
STaria said:
Anyone have a good estimate of what the max safe temperature for the armv6 cpu is? I have setCPU configured to throttle back at 46 degrees, but could that limit be safely set higher?
Click to expand...
Click to collapse
Curious about this too, I have mine at the default of 50 °C
Sent from my Liberty using XDA Premium App
What I was able to find out in the past was that a mobile phone cpu could safely reach up to 80-90°C. The motherboard and/or components on the motherboard can start to fail around 65-70°C. And for a lithium-ion battery it's best to keep the temp under 50°C for longevity, 60°C is absolutely going to affect battery life. I was never able to find anything specifically on the armv6 or where exactly the temp sensor is on the Aria. I have setCPU configured to throttle back at 46°C, and I have the charging profile throttled back because of the heat generated when charging.
Just remember that the temps being monitored are the battery temps. The aria doesn't have the ability to measure actual cpu temps.
Sent from my cm7 Aria.
CallMeAria said:
Just remember that the temps being monitored are the battery temps. The aria doesn't have the ability to measure actual cpu temps.
Sent from my cm7 Aria.
Click to expand...
Click to collapse
Right, so the CPU could probably take higher, but it's the battery that's the limiting factor.
I think I'll keep the profile as it is now, by the time the battery hits 46 that's hot enough. Don't need my Aria bursting into flames from thermal runaway.
wantabe said:
What I was able to find out in the past was that a mobile phone cpu could safely reach up to 80-90°C. The motherboard and/or components on the motherboard can start to fail around 65-70°C. And for a lithium-ion battery it's best to keep the temp under 50°C for longevity, 60°C is absolutely going to affect battery life. I was never able to find anything specifically on the armv6 or where exactly the temp sensor is on the Aria. I have setCPU configured to throttle back at 46°C, and I have the charging profile throttled back because of the heat generated when charging.
Click to expand...
Click to collapse
Thanks for the info
Sent from my Liberty using XDA Premium App

Does Under clocking Save Battery?

When I look at the stock voltage table, every processor speed bellow 378 has the same voltage. Doesn't this mean that underclocking won't save battery, or am I missing something?
Sent from my GT-I9505G using xda app-developers app
macravin said:
When I look at the stock voltage table, every processor speed bellow 378 has the same voltage. Doesn't this mean that underclocking won't save battery, or am I missing something?
Sent from my GT-I9505G using xda app-developers app
Click to expand...
Click to collapse
As far as I know this is where undervolting comes in. At least that's the path I take anyway.
macravin said:
When I look at the stock voltage table, every processor speed bellow 378 has the same voltage. Doesn't this mean that underclocking won't save battery, or am I missing something?
Click to expand...
Click to collapse
Electrical engineer here to explain.
The power used by a digital device running at a given clock speed is as follows:
P = C * V^2 * F
Where P is the power consumed, C is the capacitance, V is the voltage, and F is the clock frequency.
The capacitance of the CPU is fixed, there's nothing we can do about that.
If you lower either V or F, you'll save power. Because the voltage is squared, undervolting has more of an effect than underclocking, but both are still useful.
If you lower the frequency by 10%, you'll save 10% power.
If you can lower the voltage by 10% though, you'll save 19% power.
Personally, I lowered all of my voltages about 10%, and I don't actually let my phone underclock below 378 MHz, because it just takes it too long to respond to the power button and clock back up to a usable speed if I let it go down below that.

Need some info for core disable and enable

i want to disable both big core for best battery life. so my question is if i disable both big core then any chances for hardware failure? or something wrong with hardware?
Thanks
look4sky said:
i want to disable both big core for best battery life. so my question is if i disable both big core then any chances for hardware failure? or something wrong with hardware?
Thanks
Click to expand...
Click to collapse
no problem i am using only the smaller cores but keep the maximum frequency to the highest and minimum frequency to the lowest and set interactive governer.
askmebro said:
no problem i am using only the smaller cores but keep the maximum frequency to the highest and minimum frequency to the lowest and set interactive governer.
Click to expand...
Click to collapse
many many thanks for suggestion
look4sky said:
many many thanks for suggestion
Click to expand...
Click to collapse
ur r welcome.if u r using radon kernel set highest frequency to 1478 and lowest as 400.
askmebro said:
ur r welcome.if u r using radon kernel set highest frequency to 1478 and lowest as 400.
Click to expand...
Click to collapse
currently on stock kernel
so better to keep the big core on.but set the frequency low
why not use the hotplug option like in radon kernel?
In past experience, turning off the two big cores does not do much in increasing battery life. Besides, it will decrease performance of the device and put a larger load on the little cores.
askmebro said:
so better to keep the big core on.but set the frequency low
Click to expand...
Click to collapse
can u suggest which frequency need to set in maximum?
Ivanlai said:
why not use the hotplug option like in radon kernel?
In past experience, turning off the two big cores does not do much in increasing battery life. Besides, it will decrease performance of the device and put a larger load on the little cores.
Click to expand...
Click to collapse
thanks for sharing your experience. can you describe what is the use of hotplug?
hotplug turns off certain cores in your cpu when there is no need for the extra processing power, like when you are doing light tasks. It will turn on those cores temporarily so you get more power when doing intensive tasks.
Ivanlai said:
hotplug turns off certain cores in your cpu when there is no need for the extra processing power, like when you are doing light tasks. It will turn on those cores temporarily so you get more power when doing intensive tasks.
Click to expand...
Click to collapse
oh it is really good option for save battry

Cpu Frequencies is set to max, will it damage my hardware?

I'm on OOS + SPHINX and using kernel auditor I've set the big frequencies to max at 2803mhz and the big governors to Performance, little frequencies and governors are unchanged. Will it damage my hardware in any way?
I think not.. coz it's supposed to work that maxed out.. and the only thing that will be affected is the battery life..
santiagoruel13 said:
I think not.. coz it's supposed to work that maxed out.. and the only thing that will be affected is the battery life..
Click to expand...
Click to collapse
Okk thanks a lot bro
Not much of an effect as long as you didn't also set the minimum frequencies to max! (that will just eat up your battery and decrease its lifespan due to needing to recharge more often).
TBH, why are you messing with the CPU anyway? The 845 is so overkill for today's apps to the point where underclocking it to get better battery life is a very sensible thing to do especially if you're using Franco kernel.
Abd121 said:
Not much of an effect as long as you didn't also set the minimum frequencies to max! (that will just eat up your battery and decrease its lifespan due to needing to recharge more often).
TBH, why are you messing with the CPU anyway? The 845 is so overkill for today's apps to the point where underclocking it to get better battery life is a very sensible thing to do especially if you're using Franco kernel.
Click to expand...
Click to collapse
I'm on sphinx kernel thought
theandroidguy said:
I'm on sphinx kernel thought
Click to expand...
Click to collapse
That's... Not the point, my point was that the CPU is so powerful some Kernals under powers it to save battery without making a difference.
Abd121 said:
That's... Not the point, my point was that the CPU is so powerful some Kernals under powers it to save battery without making a difference.
Click to expand...
Click to collapse
Ohh I see, well setting it to performance was consuming a lot of battery while I was playing PUBG so I reverted it to default settings, getting 10hrs SOT

Categories

Resources