Database Users

N7 undervolted CPU

I have underclocked my CPU at 1GHz and undervolted it to -125mV and its working perfectly stable. Is it safe to undervolt even lower or should i be satisfied?

I see no reason why it wouldn't be safe. From what I know about overclocking is that worse case scenario is that it might make your tablet become unstable.
Sent from my Galaxy Nexus using xda app-developers app

More than likely it will reboot and reset values if something goes wrong. There's no harm in testing lower values so long as you don't set it on boot.
Tapatalk made me send this.

jshashwat93 said:
I have underclocked my CPU at 1GHz and undervolted it to -125mV and its working perfectly stable. Is it safe to undervolt even lower or should i be satisfied?
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so.. your device is now running on negative voltage? does that mean its producing electricity instead of using it?

Each CPU is unique, it should detect a fault and just reset to stock voltage table
Sent from my Nexus 7 using xda app-developers app

simms22 said:
so.. your device is now running on negative voltage? does that mean its producing electricity instead of using it?
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Lol I meant -125mV taking the stock values as starting point. Not from 0. And that's how everyone using System Tuner refers to it..

jshashwat93 said:
Lol I meant -125mV taking the stock values as starting point. Not from 0. And that's how everyone using System Tuner refers to it..
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ahh.. then thats normal. if you get freezes or sod then its too much undervolting for your device. also, to much undervolting can actually lead to more battery drain.

You can lower it as much as you can the worse that can happen is that it reboots because the cpu required more electricity then it could get.
Lower it as much as you can is the best you can do

Safe Undervolting

Hi, I've lowered all the figures by 100mv, but I notice no difference in my battery life. Is it safe to lower the figures more?
Sent from my Nexus 7 using xda premium

Define what you mean by "safe".
Higher core voltages are used at higher clock rates in order to preserve logic margin in the face of more power supply noise and tighter timing. So, undervolting by definition means you are giving up margin.
Whether your SoC happens to have a worst-case timing path which is "fast" or "slow" relative to other devices cannot be deduced by anyone here on XDA or even at Nvidia. About the best you can hope for is some "feel good reports" about what others do with undervolting and completely undisciplined "testing". But even that provides no information about your individual chip.
good luck

Thanks for your reply. By "safe" I mean without damaging my device. And yes, it would be interesting to hear some undervolting stories. I'd quite like to extend my battery life. Cheers!
Sent from my Nexus 7 using xda premium

I've been using my nexus 7 runing a AOKP pub build by mrRobinson and franco's r47 kernel. i've undervolted the entire board by 100mv it is runing pretty solid without any noticible lag or instability. Yet every chip is diferent and can or cannot this margin you'll have to test for your self. Just leave the option 'set on boot' unticked untill your sure that your device is capable of using those kind of voltages. And don't use very large steps. Just like overclocking in fact! Try it - it runs - get a little bit lower. If it crashes you shoukd be able to reboot the nexus and the settings you've changed reseted
Sent from my Nexus 7 using Tapatalk 2

antmasi said:
I've been using my nexus 7 runing a AOKP pub build by mrRobinson and franco's r47 kernel. i've undervolted the entire board by 100mv it is runing pretty solid without any noticible lag or instability. Yet every chip is diferent and can or cannot this margin you'll have to test for your self. Just leave the option 'set on boot' unticked untill your sure that your device is capable of using those kind of voltages. And don't use very large steps. Just like overclocking in fact! Try it - it runs - get a little bit lower. If it crashes you shoukd be able to reboot the nexus and the settings you've changed reseted
Sent from my Nexus 7 using Tapatalk 2
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Thanks! Have you noticed any improvement in battery life?
Sent from my Nexus 7 using xda premium

Been testing for 2 days now! Battery seems a little bit better yet maybe placebo! But i feel it does not get has hot as runing stock voltages! It was the main reason i did the undervolt!
Sent from my Nexus 7 using Tapatalk 2

antmasi said:
Been testing for 2 days now! Battery seems a little bit better yet maybe placebo! But i feel it does not get has hot as runing stock voltages! It was the main reason i did the undervolt!
Sent from my Nexus 7 using Tapatalk 2
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Placebo
Sent from my Nexus 7 using XDA Premium HD app

For what i've read that's the truth but if the frequencies set for the soc are getting less power shoudn't it draw less power from battery? 100mv its almost 10% of the stock voltages!
Sent from my Nexus 7 using Tapatalk 2

antmasi said:
For what i've read that's the truth but if the frequencies set for the soc are getting less power shoudn't it draw less power from battery? 100mv its almost 10% of the stock voltages!
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For the SoC, whether it's leakage (V^2/R) or dynamic power dissipation (f*C*V^2), yes, you might expect let's say (0.9^2) = 81% battery use at the same operating frequencies.
OTOH, if 75% of the power drain normally is used by the LCD backlight (for instance in a "reading web pages" use case), then reducing the supply voltage will get you only 1/4 of that 20% savings - about a 5% improvement - because the power is being dissipated elsewhere. (Display, DRAM, 3G radio, WiFi radio, etc)

I agree with what you've pointed! In fact i've just taken out the undervolt because Inhad a reboot under heavy multitasking (torrent download, xbmc opened, chrome also downloading a smal file) i'm not certain that it was caused by the uv but it's possible. The Nexus started to lag and then froze completly! From time to tima i've the need of heavy multitask and it wasn't up to the task!
Sent from my Nexus 7 using Tapatalk 2

Nexus 4 overheating

I just recently got my nexus 4 and I love it there is only one gripe I have which is the CPU temperature ... I ran various tests using stability control test and just gaming . I ran stability test for 30 minutes and got the following results ( below in pictures ) .When I game for an hour it hits 48-52 C . Is this normal ? Will it affect my CPU in anyway ?
Sent from my Nexus 4 using xda app-developers app

The heat causes thermal throttling. That will reduce performance. Undervolting helps with this a lot.

dia_naji said:
I just recently got my nexus 4 and I love it there is only one gripe I have which is the CPU temperature ... I ran various tests using stability control test and just gaming . I ran stability test for 30 minutes and got the following results ( below in pictures ) .When I game for an hour it hits 48-52 C . Is this normal ? Will it affect my CPU in anyway ?
Sent from my Nexus 4 using xda app-developers app
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theres nothing wrong there, its all normal.

I don't think those temperatures mean overheating. It is indeed quite warm. It is exceptionally warm but not hot to the touch that you can't handle it.
Sent from my Nexus 4 using Tapatalk 2

So is there a fix for this ?

Where are all my computer nerds to stop all these rediculous overheating threads? 40*C in COLD for a processor. 60C is fine. It'll throttle it if it gets too hot. Come back when you hit 90C. Not trying to be mean but jeez, someone needs to open up their computer and feel how how your processor or GPU heat sink is just at idle, you'd get second degree burns touching the heatsink at full load. Its normal for processors to get hot... to a point.

username8611 said:
Where are all my computer nerds to stop all these rediculous overheating threads? 40*C in COLD for a processor. 60C is fine. It'll throttle it if it gets too hot. Come back when you hit 90C. Not trying to be mean but jeez, someone needs to open up their computer and feel how how your processor or GPU heat sink is just at idle, you'd get second degree burns touching the heatsink at full load. Its normal for processors to get hot... to a point.
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The only reason why I asked this question is because I am still new to this device, but you can't really compare a desktop cpu or gpu to a smartphones cpu/gpu.there two distinctive hardware. PS, I work with computers and a computer science major

dia_naji said:
The only reason why I asked this question is because I am still new to this device, but you can't really compare a desktop cpu or gpu to a smartphones cpu/gpu.there two distinctive hardware. PS, I work with computers and a computer science major
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Well for one thing they both run relativity warm.
Sent from my Nexus 4 using Tapatalk 2

dia_naji said:
The only reason why I asked this question is because I am still new to this device, but you can't really compare a desktop cpu or gpu to a smartphones cpu/gpu.there two distinctive hardware. PS, I work with computers and a computer science major
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i hit a 100C(cpu temp) a few times, and got the safety shutdown. youll be ok.

I tried that... Now my nexus 4 won't turn on
Sent from my Nexus 4 using xda app-developers app

dia_naji said:
I tried that... Now my nexus 4 won't turn on
Sent from my Nexus 4 using xda app-developers app
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RMA it. Don't forget to flash it back to stock first.
Sent from my Nexus 4 using Tapatalk 2

What you see in System tuner is the CPU temp and the temperature you see in stability test is the battery temp. Those temperatures are completely fine and actually really cool for this device. Now if the battery reaches 48-52 Degrees C now we have a problem. I suggest using a custom kernel and ROM to allow some undervolting for none to less throttling so your performance will not be impacted. Should give Trinity kernel a try, latest ones are USUALLY in simm's G+ page or go to the Trinity kernel thread and download it from the website. Hope I helped

Ohh no the battery's max was 40 only the CPU hits 48-52 , for me its not a problem. I just wanted to know if it was safe to continue to game.
Sent from my Nexus 4 using xda app-developers app

[Q] S4 i9505 "underclock" CPU, possible?

Battery life on this phone is abysmal - on a fresh phone. Didn't restore much from titanium backup.
Would like to drop the CPU down a good 25% or so, can this be done without too much stress? It's an unbranded, rooted i9505 in Australia.
I suspect I'll need to flash something to do so, is that right?

wizzbang3 said:
Battery life on this phone is abysmal - on a fresh phone. Didn't restore much from titanium backup.
Would like to drop the CPU down a good 25% or so, can this be done without too much stress? It's an unbranded, rooted i9505 in Australia.
I suspect I'll need to flash something to do so, is that right?
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Click to collapse
Mines telstra stock rooted using faux kernel and my battery life is superb
Sent from my GT-I9505 using xda premium

It must be asked in Q/A Subforum buddy.

Ausboy 2011 said:
Mines telstra stock rooted using faux kernel and my battery life is superb
Sent from my GT-I9505 using xda premium
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Define "superb" for me.

Apologies for jumping in here. Can you define abysmal too? I would say my battery life is more than double my S2 (that was Cyanogen niggtlies but this is currently djembey's slim). Biggest drain is usually the 3G but I have that off most of the time. It is hard to compare to be fair as we will all use different settings but I have a lot of the bloat removed or disabled, power save on and screen at half brightness. How is yours setup as maybe we can shyc settings a little to compare more closely.

Ausboy 2011 said:
Mines telstra stock rooted using faux kernel and my battery life is superb
Sent from my GT-I9505 using xda premium
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If the reason to underclock is to save more juice, you should understand that the phone doesn't work on 1,9ghz most of the time, on average it's 200-800mhz depending on task, so you would not probably win a lot battery if you underclock let's say to 1.7 unless you're a heavy gamer.
Sent from my GT-I9300 using xda premium

beeboss said:
If the reason to underclock is to save more juice, you should understand that the phone doesn't work on 1,9ghz most of the time, on average it's 200-800mhz depending on task, so you would not probably win a lot battery if you underclock let's say to 1.7 unless you're a heavy gamer.
Sent from my GT-I9300 using xda premium
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I know this tread is already pretty old, but that answer is only partially true.
On stock configuration the GS4 uses the 'ondemand' cpu gouvernor. That gouvernor ramps up the cpu speed to the max when cpu activity is detected and will then slow down the cpu depending on the task. So everytime you open/close an app the cpu is running at 1.9ghz. (At least that I heard/experienced) using a custom kernel you can choose a different gouvernor which is more battery friendly, or lower the max cpu speed(from 1.9 To for example 1.7ghz). You can also lower the min cpu speed so that when the device is idle, it will consume less power (I think standard is around 350mhz and I put mine on 189). Some kernels even allow to underclock the GPU. Undervolting will also save battery.
In short: using a custom kernel you can really save some battery, increase performance, or get a better balance between the two, but you will have to take the time to find the settings that work best for you. I personally use KT kernel, with an overclocked CPU and GPU, but I also undervolted them both by 75mV, and with some tweaking with settings for when the screen is turned off, my battery lasts longer than stock configuration.
Correct me if I'm wrong on something, I'm not a Cpu expert
And sorry for bad english

wizzbang3 said:
Battery life on this phone is abysmal - on a fresh phone. Didn't restore much from titanium backup.
Would like to drop the CPU down a good 25% or so, can this be done without too much stress? It's an unbranded, rooted i9505 in Australia.
I suspect I'll need to flash something to do so, is that right?
Click to expand...
Click to collapse
Check this out, if you long press the power saving icon in the notification pull down, it will bring the settings for it, Uncheck all but the cpu. It will run no higher than about 1.3 ghz and is plenty fast for all tasks. I use that setting on the s4 and note 3. I never ran into any lag except TouchWhiz home launcher but I use Nova Launcher anyways.
You will see a better battery life as well.

Nexus 4 thermal throttling fix

The nexus 4 is definitely a great phone for a low price.But people are not buying this phone because of this THERMAL THROTTLING.so,people listen nexus 4 even runs smooth with thermal throttling going on.so, this fix is for people who just dont want thermal throttling.Before we start,this fix requires ROOT and a custom recovery.And a custom kernel needs to be flashed.so if you do any damage to your phone by doing this,I'm NOT RESPONSIBLE.
So first download the faux kernel for nexus 4(codename mako. if you see mako on faux website its for nexus 4) from here: Faux's website which i cannot post because im new to XDA. you can find it by googling for faux kernel website.I recommend the TBM kernels such as mako-jb-kernel 016 tbm which lets you overclock CPU to 1.83 Ghz.But theres also TBU kernels which support overclocking to 1.94 GHz.
Step 1 now download a faux kernel of your choice.
Step 2 paste the kernel to your mobile
Step 3 Boot into recovery mode
Step 4 Wipe cache
Step 5 Wipe dalvik cache
Step 6 Install .zip kernel
Step 7 Reboot your phone
Step 8 Now you have to buy the faux123 kernel enhancement program from play store(this app is from faux and this has intelli-thermal built in it)
Have fun.the faux app lets you select CPU frequencies also

What.
Sent from my Nexus 4 using Tapatalk 4 Beta

With his enhancement app yes you can control throttling but the problem is that because the phones CPU is getting way too hot, so increasing the throttle threshold or limit basically makes it so when your gaming, it makes things smoother however your CPU is burning faster.
Sent from my Nexus 4 using xda app-developers app

what is qualcomm's default throttling temperatures?

notbrodie said:
what is qualcomm's default throttling temperatures?
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it throttles to 1.3 or sometimes to 1.2 ghz when temp is 37C and to 1.1 ghz when temp is 39C

XxLostSoulxX said:
With his enhancement app yes you can control throttling but the problem is that because the phones CPU is getting way too hot, so increasing the throttle threshold or limit basically makes it so when your gaming, it makes things smoother however your CPU is burning faster.
Sent from my Nexus 4 using xda app-developers app
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No it has a thermal manager which controls the heat.if it heats up it automatically turns off 1 or 2 cores so that means 2 cores wil still run normally but the other 2 cores will shutdown.
Understood??

NexusMobileGamer said:
No it has a thermal manager which controls the heat.if it heats up it automatically turns off 1 or 2 cores so that means 2 cores wil still run normally but the other 2 cores will shutdown.
Understood??
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No **** why do you think it's turning off the cores? Because it's getting to hot
Sent from my Nexus 4 using xda app-developers app

meh.. you have root? disable throttling then, both battery and cpu throttle, then go on enjoying your device.

simms22 said:
meh.. you have root? disable throttling then, both battery and cpu throttle, then go on enjoying your device.
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Meh then have a fried CPU over time itll kill it from getting way to damn hot.
Sent from my Nexus 4 using xda app-developers app

XxLostSoulxX said:
Meh then have a fried CPU over time itll kill it from getting way to damn hot.
Sent from my Nexus 4 using a app-developers app
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i always turn off throttling, on every device i own(ed). they all live long lives, and are the best performers around(for their model). they never ever got damaged because of it, and im an extrely heavy user. my n4 has had all throttling disabled since jan 14th, and its still going strong. the difference is that i never complain that my phone turns down cpu speed, or does my phones performance get slowed down.

Just so you know
simms22 said:
i always turn off throttling, on every device i own(ed). they all live long lives, and are the best performers around(for their model). they never ever got damaged because of it, and im an extrely heavy user. my n4 has had all throttling disabled since jan 14th, and its still going strong. the difference is that i never complain that my phone turns down cpu speed, or does my phones performance get slowed down.
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I agree with you.And who dont agree with me,just know that your CPU will not be burned.Cause Fauxclock has a thermal manager of its own named intelli thermal.

NexusMobileGamer said:
I agree with you.And who dont agree with me,just know that your CPU will not be burned.Cause Fauxclock has a thermal manager of its own named intelli thermal.
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Yes, but if you disable it to have maximum performance clearly you're not throwing s*** , which in turn in the long run may burn your CPU
Sent from my Nexus 4 using xda app-developers app

XxLostSoulxX said:
Yes, but if you disable it to have maximum performance clearly you're not throwing s*** , which in turn in the long run may burn your CPU
Sent from my Nexus 4 using xda app-developers app
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The nexus 4 throttling is caused by the battery reaching a certain temperature not the CPU. It's poor design/cooling system causes heat to build up which raises the temperature of the battery. Once it reaches a low 37 degrees the cpu/gpu are downclocked even if they are well within their limits.

spix123 said:
The nexus 4 throttling is caused by the battery reaching a certain temperature not the CPU. It's poor design/cooling system causes heat to build up which raises the temperature of the battery. Once it reaches a low 37 degrees the cpu/gpu are downclocked even if they are well within their limits.
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the n4 has a battery temp throttle AND a cpu temp throttle.
i generally disable both the battery and cpu temp throttles, but leave both safety temps as is. for those that say "oh, the extra heat will eventually ruin the phone".. the temp doesnt get any hotter than it does when you normally use your phone, the difference is that you dont get throttled. and even if there was extra heat because of, im not planning on having my phone for the amount of time that the extra heat will take to ruin the phone(years).