Database Info

Undervolting FAQ

I read a lot about undervolting on here and i think i have an idea about what it does but i may be way off, and im sure each device is different. in pimp my cpu there are multiple options, and while this sounds newbish i think this should be explained to folks in some more detail.
this is what im assuming.
undervolting allows for less power consumption.
UV on higher OC levels controls power spikes to the CPU?
what is a safe level to UV and at what frequencies specific to the G2x
i am reading up on this, to get a better idea. http://www.android.net/forum/android-rooting/58117-droid-x-guide-undervolting-guide.html

Here's my understanding of the whole undervolting thing..
In order to maintain stable operation across devices with varying production quality (not all chips are created equal), manufactures use voltage levels higher than necessary for most devices. They cater to the least common denominator. But most phones will still operate reliably at a lower voltage. By undervolting you can extend your battery life and ward off chip killing heat. This all becomes even more important when overclocking. When you overclock your device you increase the power usages (those extra megahertz aren't without cost). This increases both the drain on your battery and the heat produced by your CPU. Undervolting helps to offset both issues.
As for the proper undervolting levels...that will vary with the tolerance of each individual device. But I'm sure someone can provide some general guidelines...sorry I haven't undervolted the g2x yet and don't want to steer you wrong.
Hope this helped...

Good info. I dropped mine .25 on each higher level. So ill see how it goes
G2x with CM7 and faux kernel

what confuses me on this topic is the "it's different for each device" phrase that I keep reading. Is this in reference to the rom/kernel that is being used or is it specific to apps installed/how the phone is used.. or is it a combo of both?
It's confusing me because its seems that OC/UV is hardware specific and each phone has the same hardware. So I don't quite get this "it's different for each device" thing..

schmit said:
It's confusing me because its seems that OC/UV is hardware specific and each phone has the same hardware.
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Each phone doesn't have the same hardware....for example, G2X has an nvidia tegra 2 and the nexus s has a hummingbird.

i think you mean this.
cybereclipse said:
Each phone doesn't have the same hardware....for example, G2X has an nvidia tegra 2 and the nexus s has a hummingbird.
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yes all g2x's have a tegra 2 chip.
But production does not always produce the same tolerances for all the chips.
ussually(with the quality control apparently given to the g2x who knows) but ussually all chips are tested and every chip that is in a g2x will perform reliably at 1ghz as it is specified and sold at.
some of these will run reliably at 1500 or better while some will not go over 1100 without starting to get unreliable.
example is the droid 1 was sold at 550 mhz. they did an update that upped it to 600mhz so they knew all chips were tested to be ok at that threshold. Mine would run at 1200 reliably no overheating(except running flash) no reboots.
with 2 different kernels. there was another kernel that they messed with the voltages so that i would get constant reboots even at 700mhz.
some droids would not run over 700 without experiencing problems.
So yes the tegra 2 chips is the same but the abilities of it can be different. they are guarenteed to run at the speed they are sold at but most will function at a much higher speed without problems while some will not.
oh just thought of a great example. the AMD tri-core processors.
those are quadcores where 1 of the cores did not pass the tests but the other 3 did so instead of scrapping the entire chip they turned off the bad processor and sold it as a tricore. there are motherboards out there that allow this core to be turned back on and many have done this and it works just fine. its just that core didnt pass whatever minimum they set on it even though it was perfectally functional they determined that if it got to this temp or didnt run at this speed(over what it was sold at) it didnt pass.
So while this kernel at this voltage may run fine on your phone it may caused reboots or lock ups on others.
hope this makes some sense.

eagle1967 said:
yes all g2x's have a tegra 2 chip.
But production does not always produce the same tolerances for all the chips.
ussually(with the quality control apparently given to the g2x who knows) but ussually all chips are tested and every chip that is in a g2x will perform reliably at 1ghz as it is specified and sold at.
some of these will run reliably at 1500 or better while some will not go over 1100 without starting to get unreliable.
example is the droid 1 was sold at 550 mhz. they did an update that upped it to 600mhz so they knew all chips were tested to be ok at that threshold. Mine would run at 1200 reliably no overheating(except running flash) no reboots.
with 2 different kernels. there was another kernel that they messed with the voltages so that i would get constant reboots even at 700mhz.
some droids would not run over 700 without experiencing problems.
So yes the tegra 2 chips is the same but the abilities of it can be different. they are guarenteed to run at the speed they are sold at but most will function at a much higher speed without problems while some will not.
oh just thought of a great example. the AMD tri-core processors.
those are quadcores where 1 of the cores did not pass the tests but the other 3 did so instead of scrapping the entire chip they turned off the bad processor and sold it as a tricore. there are motherboards out there that allow this core to be turned back on and many have done this and it works just fine. its just that core didnt pass whatever minimum they set on it even though it was perfectally functional they determined that if it got to this temp or didnt run at this speed(over what it was sold at) it didnt pass.
So while this kernel at this voltage may run fine on your phone it may caused reboots or lock ups on others.
hope this makes some sense.
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Nice...that was much better than my explanation.

cybereclipse said:
Each phone doesn't have the same hardware....for example, G2X has an nvidia tegra 2 and the nexus s has a hummingbird.
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lol. dude, I'm in the g2x forum.. not the "whatever phone ya wanna talk about" forum. I was referring to the g2x's having the same hardware, lol.
Thanks to the other guy for the awesome explanation

What are the dangers of an overclocked CPU/ undervolted kernel?

Please excuse me for my ignorance, but I don't know much about these kinds of topics.
I wanted to know if anybody could be kind enough to explain the dangers and negatives of an overclocked CPU and an undervolted kernel?
I know their benefits because of some research I did, but I could never find a concrete answer explaining the negatives and dangers.
I've heard some horror stories of overheating handsets that get so hot that internal components fry, heard about damaged radios that need to be replaced, and loss of signal. But I'm not entirely sure if those instances are correlation instead of causation.
Any insight would be greatly appreciated. Thank you!
-Chris
Sent from my HTC Sensation 4G using XDA App

The general issue that applies to both modifications is that you are using the chips outside their specifications. Their whole behavior might no longer be as expected.
This is usually happening at such low level and in a so small range that it doesn't affect normal use.
Overclocking will definitely produce more heat. That's why people that overclock pcs to insane levels use non-standard cooling like dry ice or even liquid nitrogen.
As you can't change the way your phone will transport heat, there's only very limited room for overclocking.
The phone is designed to switch itself off if it gets too hot, however this is not something one should rely on.
Not sure about any specific risks of undervolting, but the general issues will definitely apply. Noone can guarantee for stuff to work as expected when you run components outside the specifications, as they were tested to run safe only inside the specs as supplied by the manufacturer.

It can cause permanent CPU damage which can lead to you bricking your phone, but the chances of that aren't that great. Usually if you undervolt too much, your phone will just reboot.

Stability is the biggest issue. It can put the components too far out of their comfort zone.

Unstable, unexpected behaviour and/or (in very strange cases drastically) reduced life expactancy. However, if you do undervolt your cpu, the only/main issue becomes unstable.
In my experience (lot of pc overclocking), you will notice when your material can't keep up with the settings and if you change it (back), no problems will occur.

aNYthing24 said:
It can cause permanent CPU damage which can lead to you bricking your phone, but the chances of that aren't that great. Usually if you undervolt too much, your phone will just reboot.
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So would you say it's worth the risk to flash a ROM that has an overclocked CPU and undervolted kernel? I'm so scared to damage my device
Sent from my HTC Sensation 4G using XDA App

LPChris47 said:
So would you say it's worth the risk to flash a ROM that has an overclocked CPU and undervolted kernel? I'm so scared to damage my device
Sent from my HTC Sensation 4G using XDA App
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Yes I would, in a way the lower voltage cancels out the higher voltage, and even produces less heat overall. There are no dangers of undervolting AFAIK, saving battery is good, although if you set the volt extremely low the phone will freeze up. Devs put the volt at a good level but most of the time you can lower it by a notch or increase it for no reason. If this phone ever gets 2GHz clock that would be a danger to run at, because the voltage would be insane.

[Q] overclocking droid charge

How can I go about overclocking my droid charge? I am running TWEAKSTOCK 1.0 rom and was wondering how to overclock my charge?

I haven't seen any over clockable kernels so until then I don't think you can.

Download tegrak overclock from the market if u want to overclock. I'm running mine at 1.2 and undervolted and it works great.
Sent from my SCH-I510 using XDA App

Chitala383 said:
Download tegrak overclock from the market if u want to overclock. I'm running mine at 1.2 and undervolted and it works great.
Sent from my SCH-I510 using XDA App
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With the same kernel?

Well, if you actually searched, this would be clearly stated in many threads.
For GB overclocking, use Tegrak for now, until we can get an actual OC kernel up and running. I think Tegrak will work on the stock kernel as long as you're rooted, as it uses a module to modify the CPU frequency.
Sent from my SCH-I510 using xda premium

Another tegrak user here. I paid for the ultimate version for undervolt and start on boot
Sent from my SCH-I510 using XDA App

xdadevnube said:
Another tegrak user here. I paid for the ultimate version for undervolt and start on boot
Sent from my SCH-I510 using XDA App
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Are there noticeable improvements with overclocking/undervolting?
Also what settings do you use?

BattsNotIncld said:
Are there noticeable improvements with overclocking/undervolting?
Also what settings do you use?
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Take what I say with a grain of sand, I'm expressing my views without much scientific validation.
Keep in mind that overclocking is like icing on the cake. There are far more beneficial things like changing the scheduler to noop or deadline. Fugu tweaks and V-6 are highly recommended to improve responsiveness and improve your launcher resiliency. That said, I feel overclocking has its place and helps in many cases. I've noticed, in general, various tasks and some web-browsing will benefit from the increased clock speed. Some things don't ramp up the CPU very much and you won't notice much difference in that case.
I monitor my CPU usage with CPUNotify as well as OS Monitor.
I monitor the CPU temps with TempMonitor (it allows for a notifcation icon that shows the CPU temp.)
I use StabilityTest to check for overclock settings stability. The cool thing about Tegrak is that when you apply overclock settings on boot (paid version only) and you choose settings that crash the phone, the settings don't apply until most of the phone is already booted up, so you aren't stuck in an infinite boot loop of crashing fun. You should be able to simply change up the settings after they apply since the phone will be mostly idle by the time Tegrak settings are applied.
As for settings...
I use the Interactive X governor. I prefer this governor for its simplicity and ability to ramp up to high CPU clock speeds quickly. I enable the governor by typeing "su" and "ix enable" in Terminal Emulator when on Imoseyon's 4.0 kernel.
I change the "scaling min" to 200Mhz to avoid instability when CPU usage ramps down quickly.
Currently at CPU Level 0 I am at 1265mv Core Voltage, 1100mV (unchanged) Internal Voltage, and 1200 Mhz Frequency.
I don't actually change other CPU Levels.
Lately I've been just keeping at eye on temps so I haven't achieved my desired clock speed of a relatively low-voltage 1.4Ghz to 1.5Ghz.
Overclocking is very dependent on the particular sample you get. Some of us have "Golden Chips" and some of us have duds.
Your CPU should be totally safe at temps around 130 degrees F, although I suspect that it could even take higher sustained temps well above that if it needed. I don't actually know, this is speculation.
I like to keep my temps low in general, I rarely crack 100F with my current settings (weather is cool here.)
Overclocking computers is one of my hobbies, and its fun to dive into the phone side of things. I haven't been able to find a whole lot of information regarding overclocking the Hummingbird processor. People have overclocked to 1.6Ghz. Stability tests are essential to improve the reliability of your overclock. Die hards will run the tests for 24 hours to weeks in the computer realm. At least with computers its better understood how the stability test actually works. I run 24 hours of Orthos blend mode (Prime95) on each core.
With phones, its hard to say if it will truly be stable.
I test for an hour on the phone with StabilityTest and call it good. Hopefully in the future more information will come to light regarding how to properly overclock.
Remember, the other side of the coin is underclocking and undervolting. If you drop your voltage, you should see a nice increaes in battery life. If you drop your clocks, then you can drop your voltage even more. If you get your phone dialed in to where there isn't much background apps sucking juice- a phone that is UV/UC'ed should have excellent battery life.

Does anyone else read noop as nope?
What's the difference between internal and CPU voltage?
Also, I hope you know that Orthos does not scale well across multiple cores. You are essentially relying on Task Manager to put the load on different cores.Orthos was originally made with dual cores in mind.
Sent from my SCH-I510 using xda premium

kvswim said:
Does anyone else read noop as nope?
What's the difference between internal and CPU voltage?
Also, I hope you know that Orthos does not scale well across multiple cores. You are essentially relying on Task Manager to put the load on different cores.Orthos was originally made with dual cores in mind.
Sent from my SCH-I510 using xda premium
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Apparently little is known in the public domain about Internal voltage. I have been unable to find good information regarding Internal voltage. Knowing little about the architecture of the SOC, I suspect it is a voltage that controls different parts of the SOC hub. I suspect that you could say its synonymous with a computer motherboard's voltage (although there are several.)
I find it interesting that, as far as I can tell, few people have increased Internal voltage much even though they may achieve a clock speed of 1.6GHz by increasing CPU voltage.
In any case, I have heard reports of instability by going to low, as would be expected. I haven't found the need to increase Internal voltage yet.
P.S. You can run an instance of Prime95 on each "core" or one instance of Orthos per two "cores" and still be able to test stability reliably. You have to set Core affinity, and I usually set it so that each core and hyperthreaded core each get an instance of Orthos. In this case, each core's usage will be 100%.

xdadevnube said:
Apparently little is known in the public domain about Internal voltage. I have been unable to find good information regarding Internal voltage. Knowing little about the architecture of the SOC, I suspect it is a voltage that controls different parts of the SOC hub. I suspect that you could say its synonymous with a computer motherboard's voltage (although there are several.)
I find it interesting that, as far as I can tell, few people have increased Internal voltage much even though they may achieve a clock speed of 1.6GHz by increasing CPU voltage.
In any case, I have heard reports of instability by going to low, as would be expected. I haven't found the need to increase Internal voltage yet.
P.S. You can run an instance of Prime95 on each "core" or one instance of Orthos per two "cores" and still be able to test stability reliably. You have to set Core affinity, and I usually set it so that each core and hyperthreaded core each get an instance of Orthos. In this case, each core's usage will be 100%.
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Internal SOC voltage...maybe akin to northbridge or southbridge voltage? When OCing a computer you have to keep the northbridge within a nominal voltage of the CPU frequency (if that makes sense). Too much of a discrepancy makes the computer unstable. Increasing the southbridge voltage increases the memory overclocking stability with large amounts of RAM, and obviously, when you overclock a processor you are also overclocking memory.
Maybe we could ask the developer? Although he is Korean and we may not be able to get our point across.
For stability testing on PCs I recommend OCCT. Scales well over Multiple cores and also allows GPU and power supply stability testing.
Sent from my SCH-I510 using xda premium

kvswim said:
Internal SOC voltage...maybe akin to northbridge or southbridge voltage? When OCing a computer you have to keep the northbridge within a nominal voltage of the CPU frequency (if that makes sense). Too much of a discrepancy makes the computer unstable. Increasing the southbridge voltage increases the memory overclocking stability with large amounts of RAM, and obviously, when you overclock a processor you are also overclocking memory.
Maybe we could ask the developer? Although he is Korean and we may not be able to get our point across.
For stability testing on PCs I recommend OCCT. Scales well over Multiple cores and also allows GPU and power supply stability testing.
Sent from my SCH-I510 using xda premium
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Well, I have heard of slight Internal Voltage increases being necessary for high overclocks on Hummingbird. I have heard dropping it causes major instability. I would guess that it doesn't need to be modified for modest overclocks.
I did quite a bit of web searching trying to find conclusive guides or overclocking results for Humminbird to no avail.
I use ATI Tool for checking GPUs, but OCCT may be better. It seems OCCT has improved a fair bit, I may use it.

xdadevnube said:
Well, I have heard of slight Internal Voltage increases being necessary for high overclocks on Hummingbird. I have heard dropping it causes major instability. I would guess that it doesn't need to be modified for modest overclocks.
I did quite a bit of web searching trying to find conclusive guides or overclocking results for Humminbird to no avail.
I use ATI Tool for checking GPUs, but OCCT may be better. It seems OCCT has improved a fair bit, I may use it.
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Probably because no one has taken the time to write one. Not exactly in high demand. I knew of one "guide" but the site has been down for quite some time.
Of course there are noobs guides but nothing quite in depth. I suppose people don't write them because there are obvious limits set by the kernel dev, and anything beyond that requires someone who obviously knows what they're doing, which defeats they purpose of a guide.
Sent from my GT-P1000 using xda premium

Overclocking's effect on phone's lifespan

It seems to me many people overclock their HOX up to around 2ghz through various kernels/ROMs. I'm relatively new to Android phones but I do have a fair amount of OC experience on PC. The thing is, on PC the OC is generally well studied/tested by many people with well established thresholds, and people often upgrade their cooling system to accommodate OC. If stock cooler is used, there are usually established conservative limits. Furthermore, there are programs that stress test the setup to detect any instability. It's known that OC decreases hardware's lifespan, but if you do it right, that decrease can be negligible because of the realistic lifespan of PC.
Our phone is tiny and its cooling is not upgradable. If we overclock it by 30%, what effect will it have on its lifespan? Is there something about these S4 CPU's that I don't know about? Were they made to be able to easily handle the OC without any significant heat increase?
Please share your thoughts.

I'm not sure the true clock speed of the krait but I've read that most CPUs are under clocked by default
So I would think the impact would depend on its true clock speed
It also depends on how long you intend on keeping the phone. I change phones quite often.
If you intend on keeping it two years then I'd suggest just be safe and not sorry. This phone is fairly new and not much is know of long term issues quite yet
Sent from my One X using Tapatalk 2

i know the S4 can be clocked at different speeds by default (1.5-1.7 GHz Dual-core Krait). there is also superpi for android to test stability. it seems 1.5 - 2.0 GHz doesn't give much of a performance boost as far as benchmarks go imo. If we could somehow manage to tweak memory timings like on a pc that would be awesome.

OC = shorter life........to what extent I cannot say. But it's a fact
Sent from my HTC One X+ p_type 0.91.0

My P3 that was a stock speed of 733 an runs at 1.8ghz for last 6 years with factory cooling says don't worry about it.
Also, i couldn't hit 229ms in pi until 2ghz.
If your worried about shortening the life span, by over clocking, its not for you honestly.
WR
Sent from my One X

you overclocked a Pentium 3 733 to 1.8 ghz? i don't believe that at all..

DvineLord said:
you overclocked a Pentium 3 733 to 1.8 ghz? i don't believe that at all..
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You are correct, its a typo, it should read 1.4 and not 1.8.
WR
Sent from my One X

[Q] Overclocking but no Exploding

Hi XDA Community. I use Trinity Kernel by Morfic and i was wondering if it is okay to have an Overclocked Nexus 5 and use the phone at a regular basis like a normal stock clock Nexus. I don't want My phone to just randomly explode because of overclocking it. One of the features the kernel has as said at his/her XDA thread is "Up to 2726MHz (higher clocks will vary from device to device)". Is that frequency trustworthy when just using the phone normally or is that a benchmark frequency?

MaLing15 said:
Hi XDA Community. I use Trinity Kernel by Morfic and i was wondering if it is okay to have an Overclocked Nexus 5 and use the phone at a regular basis like a normal stock clock Nexus. I don't want My phone to just randomly explode because of overclocking it. One of the features the kernel has as said at his/her XDA thread is "Up to 2726MHz (higher clocks will vary from device to device)". Is that frequency trustworthy when just using the phone normally or is that a benchmark frequency?
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Don't overclock that high. 2419MHz at most. Overclocking too high will cause more heat and throttle earlier, only useful for a short benchmark such as HWBot Prime or Quadrant (Antutu takes longer and will overheat by the time it finishes). Trinity also supports up to 3014MHz, OP hasn't been updated.

MaLing15 said:
Hi XDA Community. I use Trinity Kernel by Morfic and i was wondering if it is okay to have an Overclocked Nexus 5 and use the phone at a regular basis like a normal stock clock Nexus. I don't want My phone to just randomly explode because of overclocking it. One of the features the kernel has as said at his/her XDA thread is "Up to 2726MHz (higher clocks will vary from device to device)". Is that frequency trustworthy when just using the phone normally or is that a benchmark frequency?
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You don't want to push the phone too much I think the Nexus 5 runs at 2.3 GHz. 2.7 MAY not be too bad but honestly, the phone runs pretty smooth as is. What benefits are you looking for from overclocking?

Thanks guys for sharing your knowledge. You know.. To get the MOST out of the Phone while at the same time being Safe.

if you really wanted, the phone won't explode if you run it at 3015mhz either. the worst that will happen is that your phone won't be able to run that high, and will freeze and reboot.
and don't listen to all.. run your phone how YOU like. yes, it'll cause a little(not much) more heat, and will throttle a little earlier, but that's why people like me disable throttle, so that's a non issue. I run my phone at high CPU speeds all the time, and use 2880mhz high/300mhz low quite often. just because I feel like it, no other reason.
oh, I run trinity as well, and do all of Trinity's testing

MaLing15 said:
Thanks guys for sharing your knowledge. You know.. To get the MOST out of the Phone while at the same time being Safe.
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It's just what @jsgraphicart said. You're not really getting more out of your phone by overclocking. It's not going to run smoother, and most games don't lag anyway so they probably won't run better. I think most people just do it for benchmarks or just to check if it can run on a certain clockspeed.
Also what @simms22 said. You can do it if you want to, but simply because you want to because as far as I know there aren't really any benefits.

Back in my Palm Pre days, we used to overclock that thing to 1GHz. The default setting was 500MHz. I think it was even pushed to 1.2GHz. And it ran fine. But back then, you could tell the difference between a little lag at 500MHz and smoothness at 1GHz. With this phone and how Android has gotten smoother with every update, it's kind of hard to see any difference when overclocking. It will be smooth regardless.

oh, benefits, not really. a little more speed, yes. bit I would never call it a benefit, unless the speed difference was drastic, and its not.

As mentioned, overclocking the CPU can actually turn out to run slower because of aggressive thermal throttling. You could disable or extend the thermal throttling, but 2.3Ghz is already plenty fast for today's mobile software so you won't notice any difference in day to day usage.

bblzd said:
As mentioned, overclocking the CPU can actually turn out to run slower because of aggressive thermal throttling. You could disable or extend the thermal throttling, but 2.3Ghz is already plenty fast for today's mobile software so you won't notice any difference in day to day usage.
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Even if you run your phone at 2880MHz/3014MHz/whatever with thermal throttle off, you can't really do anything too intensive as it'll hit 105C and shutoff lol

Lethargy said:
Even if you run your phone at 2880MHz/3014MHz/whatever with thermal throttle off, you can't really do anything too intensive as it'll hit 105C and shutoff lol
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actually, no, youre wrong. when you run your phone at 2880/300 or 3014/300, you phone will hardly scale up that high, sometimes it will. you wont see any real difference between those high cpu speeds and running it at 2265/300. and battery will be similar. the difference will be if you run it at 2880/2880 or 3014/3014. now i run my phone at 2880/300 very often, and you know i disable thermal throttle. yet, i see no difference in temperatures, except if im doing something thats very cpu intensive.

simms22 said:
actually, no, youre wrong. when you run your phone at 2880/300 or 3014/300, you phone will hardly scale up that high, sometimes it will. you wont see any real difference between those high cpu speeds and running it at 2265/300. and battery will be similar. the difference will be if you run it at 2880/2880 or 3014/3014. now i run my phone at 2880/300 very often, and you know i disable thermal throttle. yet, i see no difference in temperatures, except if im doing something thats very cpu intensive.
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Ah true. But still, a bit easier to hit it if doing something intensive Not to mention it may be a little unstable on some devices

Lethargy said:
Ah true. But still, a bit easier to hit it if doing something intensive Not to mention it may be a little unstable on some devices
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on some devices??? on most devices! anyways, stability is overrated

LOL...no explosions on XDA allowed!