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.
Click to expand...
Click to collapse
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
Click to expand...
Click to collapse
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.
So I have a few apps... Voltage Control, SetCPU, No-Frills CPU... but I've honestly been a bit weary to use them. I want the best battery life since I'm a heavy user, but I also don't want to overclock/set voltage to a point where I'll screw up my phone. I'll admit that I'm a novice user when it comes to voltage/overclocking, but not when it comes to ROMs, kernels, bootloaders, etc. I work with those all the time, but really trying to get the most out of the battery and CPU.
There's this thread I found that has someone's settings on it, but don't know if its good or how much this guy knows(no offense to him):
http://forum.xda-developers.com/showthread.php?t=1356211
Anyone got any insight or perhaps screenies of their optimally tested settings? VERY VERY appreciated to anyone that can help.
jgruberman said:
So I have a few apps... Voltage Control, SetCPU, No-Frills CPU... but I've honestly been a bit weary to use them. I want the best battery life since I'm a heavy user, but I also don't want to overclock/set voltage to a point where I'll screw up my phone. I'll admit that I'm a novice user when it comes to voltage/overclocking, but not when it comes to ROMs, kernels, bootloaders, etc. I work with those all the time, but really trying to get the most out of the battery and CPU.
There's this thread I found that has someone's settings on it, but don't know if its good or how much this guy knows(no offense to him):
http://forum.xda-developers.com/showthread.php?t=1356211
Anyone got any insight or perhaps screenies of their optimally tested settings? VERY VERY appreciated to anyone that can help.
Click to expand...
Click to collapse
there is no rule. every cpu is different. very different. my captivate took a lot of effort to get a meer 1300 mhz but my infuses get 1600 no problem at all. some infuses wont go to 1600 but more will go to 1500 than galaxy s's. they probably held out the best testing cpu's for the higher clocked phone.
for battery life try clocking @ 800 mhz and dont use screen off profiles just because it looks like a good idea to slow the cpu when you arent really using it(causes problems if the max freq is too low with some kernels) and test stability with your uv settings, go down a little at a time, for max frequency uv from the top down, for battery life go from the bottom up and disable the upper freqs if they become unstable. this is because rapid voltage changes can contribute to instability. too much differential will cause crashes if the uv is extreme or the oc is extreme.
at some point though the cpu settings will have a limited effect. the radios use battery as well. manage your screen brightness and try edge only with the screen off using any number of apps that manage the radio. try one of entropys kernels to avoid a feature of the wifi chip (or was it bt) from sucking power when in proximity of another device with the same chip. turn off sync if you dont need push emails from gmail or real time facebook updates and if you really need battery life get in the habit of togging wifi and bt and gps on and off depending on need. i do none on this because i always found the battery life adequate on samsung phones but on my aria, well it was a must and prolly why people hate android. htc and battery life dont go together unless you manually manage the phone functions.
That's a great bunch of information. I currently keep my Brightness at 0%, GPS off, Wifi only ON when I'm at work when the charger is plugged in.
I guess I'm more concerned with the undervolting than the overclocking. I'd rather preserve the battery life with undervolting... the overclocking isnt a HUGE concern, but it'd be nice to see. Regardless, if you have any "ideal" UV settings, or ones that have worked for YOUR Infuse(assuming you have one), then I'd love to see them.
at one point i had -200mv on every freq from 100-1600mhz and no crashes. i started manually editing the uv script (voltage control is only able to write -200 into the script unless you have the pay version) and forgot what i ended up with. but my first infuse was exceptional in that area. some infuses freeze above 1400 mhz no matter what voltage settings are used. about -50 seems to be safe 99% of the time with minor or no overclock across the board but you could probably go -50 down low and -100 from 400mhz up to 1200 and -50 or -75 on overclock freqs. with underclock or atleast no overclock it's probably safe to go -100 to -150. it may be safe to go much more than that as well but on a small number of phones that might be too far as it is. cpus are made on such a small scale that microns of inconsistency make large percentages of difference. many dont pass testing and qc. some are borderline for the application, some are exceptional. the smaller the architecture gets the more potential the design has for speed but the larger the variance in performance is given a manufacturing technique. obviously the manufacturing gets better and better combating this so that they can make smaller architectures they also have redundancy built in, but sometimes they just disable features of a chipset and market it as an economy version if they have a low pass rate. ever see a 3 core cpu for a pc? most are manufactured as 4 cores and on many motherboards the bios can unlock the 4th core with somewhat unpredictable results.
Again, some really great info for the technical guys such as myself. What is the best way to test the UV settings? The built in tools and stuff in SetCPU? Or is there another way that would be more effective and/or would get more realistic results?
Seems like some recurring discussion in past threads:
1 - why should we even bother overclocking if we’re not a gamer.
2 - won’t we damage our device with overclocking.
I haven’t seen definitive answers posted anywhere, and I certainly don’t have one.
Maybe in that case (I have no definitive answer), I should probably just keep my mouth shut.
It may be the case, if so let me know.
For whatever reason, I have some strong opinions and I feel it would be useful to share my opinions and the reasons I have formed those opinions.
Take them or leave them or add to them... up to you.
Point out to me if you think I am grossly mistaken.
1 - why should we even bother overclocking if we’re not a gamer.
Click to expand...
Click to collapse
There is constant tradeoff between battery and performance.
Underclocking will help you save battery. How low you want to underclock depends on what you can tolerate.
But what you can tolerate depends on your user experience, which can be dramatically impacted by use of overclocking at other times.
The perfect example for me is a program which is slow to start up. In my case it is Memento database with 1000+ records, takes a long time to read in (I think the program does some sorting every time it opens). That is a minor annoyance. If I were to underclock it will start even slower, I’m going to get impatient and set my speed back up.
But think about this:
1 - Using Tasker you can apply cpu profiles upon application launch and remove them after a predetermined length of time. I can give the program a blast of 1600M-hz when it starts, then set it back where it was after predetermined period (for example 10 seconds).
2 – Setcpu is not quite as flexible as tasker in this regard. With setcpu we can create a profile to occur when we launch the program like Memento, but we just can’t incorproate a time delay into the logic (it will stay on the higher profile as long as the program runs in the foreground).
3 - There may be circumstances where this setcpu behavior is what you want... it will give you faster response whenever the program is in the foreground, and will yield to lower priority profiles whenever the program goes to the backghround.
(I haven’t investigated how to make make Tasker and setcpu play nicely together yet).
So, if you speed up the things that cause noticeable delay for only a short time, or particular applications which seem to run slow then you can probably be more satisfied with your underclock in the other times. In the overall picture, I think the overclock capability can ironically be used as part of a strategy to save battery (unless you just like overclocking just to see things zip accross your desktop and menu’s pop in and out faster than you can blink, I’m starting to get spoiled with that behavior on my phone in its new configuration, partially from overclock..I’m sure others get even better in their configuations..).
2 - won’t we damage our device with overclocking.
Click to expand...
Click to collapse
On this I would say no, as long as you are careful about not running it in conditions that create high temperature. .
(you may have stability problems as you guys know, an entirely different subject).
The physics of the damage are all related to temperature. There are many variables affecting temperature that the designer is unaware of and so he builds in margin for the worst cause unknown future occurence (he has to consider maybe phone will be in desert with 100F ambient, and on the charger, while the user tries some heavy surfing with gps, all at the same time, so he limits cpu to 1200Mhz).
We on the other hand know what are the conditions of our phone and what it’s likely to see and what it’s doing at any given time, and setcpu provides additional ability to monitor and adjust.
Here are example setcpu profiles I came up with to protect myself from damaging temperatures (Zen's kernel A/1600)
Priority 100: If batter temperature > 50C (122F),establish conservative governor 100-400Mhz
Priority 90: If batter temperature > 45C (113F),establish conservative governor 100-800Mhz
Priority 80: If battery temperature > 40C (104F), establish conservative governor 100-1200Mhz (in the event I was overclocking, this profile will stop it when battery temp exceeds 40C, all other profiles that may invoke overclocking are lower priority than 80).
This is just from judgement, knowing that I’m normally < 104F battery temp during light use and don’t want to overclock when I’m outside that normal light use zone. Some further curtailment of cpu max frequency occurs as battery temperature climbs above that. (which I would not have even had the benefit of if I were casual user with no overclocking and no setcpu).
As long as you’re limiting temperature, you should not be worried about damage imo. By the way, of course overclocking is not the only thing to affect temperature: things like phone case (thermal insulation), charging, gps, heavy use etc all have an effect. I'm not quite sure why sometime cpu overclocking gets singled out in a dangerous category all its own without any discussion of other things that affect tempertaure.
In fairness, you may point out that what we monitor is battery temperature and not the same thing as cpu temperature. It’s a good point. Increase in heat generated at the cpu causes more of an increase in temperature at the cpu then it does at the battery. But it's question of how much different. there's a matter of how much. Why do you think it is that Samsung didn’t give us cpu temperature indication? I think because they knew battery temperature is close enough. Even on newer flagship Behemoth Samsung Note, I’ve read you still only get battery temperature, no cpu temperature. If cpu temperature was that much different, they surely would have provided a separate indication of cpu temperature (cpu is after all a much more critical component than replaceable battery).
And why should we expect battery temperature to be representative of cpu temperature on our phone, when the same is not true on a pc? I think I can answer that:
* PC has things all spread out. There is air flowing through. The air picks up heat from each component from heat sinks by convection. The component temperatures are not tightly coupled together.
* Phone (in contrast to pc) has everything compact inside one itsy bitsy case. There is no air flowing through. That means heat transfer inside the phone is not by convection but by conduction. For most effective conduction, all components are attached with high thermal-conductivity path to the phone structure and the exterior surface of the phone. The heat transfer from phone to ambient is primarily convection. So we have effective heat transfer (conduction) among the components of the phone and less- effective heat transfer (from phone to environment). It tends to tell us that there will not be big difference in temperature among phone components. The big temperature difference that occurs is between the phone and the ambient air.
I don't have access to a phone which has both cpu and battery temperature indicators. If someone does, it would be interesting to hear how close those two temperatures follow each other.
===================================================================================
Edited to add: searching other threads suggests there can maybe be a substantial differencebetween cpu temperature and battery temperature. That makes me a little less certain. At least we can use battery temperature as a gross indicator that the cpu isn't seeing excessive extra heat from other non-cpu sources while we're overclocking it. Certainly having profiles in place to limit overclocking when battery temperature is high can only help protect us. But is it a false sense of security which can lead us astray? I dunno. I have already done a stability test at 1600 for quite awhile and there's no damage in sight, so if there is any damage potential, then it is only an accumulation over time. I don't plan on leaving Fmax at 1600 all the time anyway, since it would kill the battery. My planned strategy reserves the 1600 overclock for occasional playing around, and boosts when I need them like like my Memento database. My gut says that approach is just fine. Interested in hearing any other thoughts, experiences, links that may shed light.
Introduction:
If you’re reading this, I’m going to assume that you want to learn something new. I love sharing knowledge with others, so I hope you do as well. With that being said, please understand that I’m doing this in my spare time, and have no degree of any kind on this topic. What I’ve compiled here is a pretty good guide to explain and hopefully educate some of you on a highly talked about, but widely misunderstood concept of CPU architecture.
Before we begin, I need to make sure you all understand a few basic concepts of electricity. I can’t teach you new material if you don’t know the language, right?
Terminology:
Voltage
The first term is, of course, voltage. Voltage is defined as the difference in electrical potential between two points. What does that mean, I’m sure you wonder? Well, to put it simply, think of a fire hydrant. When the valve is opened to let water into a hose, from the hydrant, it rushes in all at once to the end of the hose. It sits there in the hose until the nozzle is opened to put out the fire. The force that pushes the water forward is called water pressure, and like water pressure, voltage pushes the electrical current along as well. So, we will think of voltage itself as the force or pressure being applied behind an electrical current to keep it moving.
Amperage
Next up is the term, amperes. In short this is the electrical current itself. An ampere, or amp for short, is the actual unit of measurement for the amount of electricity passing a single point in a circuit at one time. This might seem confusing, so let’s just keep it simple and think of an amp as the electrical current itself. In the fire hose example, the amperage would be the water inside the hose.
Wattage
Last up is something called a watt. Now, this one can get tricky, so stick with me. A watt literally measures the rate of energy conversion or the transfer of energy. So, essentially, the watt measures the amount of work done over time. This is where it gets tricky and a little confusing. Wattage, in the fire hose example, would be the amount of water that the fire hose can hold. This is the work, or wattage, generated by the hose while operating under a constant flow of water. Now, that’s the tricky part right there. ‘Work’ in this example isn’t a normal 9-5 job. It is, more simply put, the overall capacity of the hose. A normal household lightbulb is rated around 60 watts. This means that while it’s on, it is producing a constant amount of light. This constant amount is 60 watts, which is its peak brightness under constant current.
So, to sum these three terms up as simply as possible, think of voltage as pressure, amperage as the current, and wattage as the capacity.
Example
One final example should help with this analogy. We’ve all seen those wacky waving inflatable arm flailing tubemen before, right? If not, or if you’ve never seen Family Guy before, it’s basically a long, nylon tube that is open at both ends. One end is attached to a fan at the bottom, while the other end is left open for air to escape. When the fan at the bottom is turned on, it begins to generate wind that inflates the tube and causes it to rise off the ground and flail about in the air. In this example, the voltage is the air pressure keeping the tube floating, the wind flowing through the tube is the amperage, and the amount of wind needed to make the tube rise off the ground is called the wattage.
Undervolting:
Myth or fact?
Let’s go ahead and start off with a bang, shall we? First, let me make it clear to you that no matter what people tell you, undervolting your CPU will not magically make your battery last five days longer than it should. I’m not saying it doesn’t save battery at all, because it does. It just doesn’t save as much as you’ve probably been led to believe. On any average smartphone battery under normal conditions, you should not expect an increase of more than a few percent while undervolting.
Does this mean you should stop undervolting altogether? Not at all! Quite the contrary, actually. Undervolting is actually a very good thing for your smart phone when you do it correctly. Undervolting has one major positive effect on your CPU: it will extend the life of your processor by allowing it to do demanding things with lower heat generation. In the tube example from before, undervolting would be like reducing the fan speed as low as possible while still keeping the tube in the air. The air pressure lowers along with the wind current, or amperage. Due to the now lower amount of pressure, the amount of wind being pushed through the tube (amperage, remember?) is lowered slightly as well. This, in turn, prolongs the life of the nylon tube itself by putting less strain on it while it’s flapping around in the breeze. It’s kind of like how a flag flying in the breeze will last longer than one you fly on the back of your truck while you drive down the highway.
Summary:
Now that we’ve learned all this, what does it all mean? Well, going back to the nylon tube example, the tube itself is the CPU. So, all three properties discussed before come into play here around the nylon tube (CPU). The air pressure forces the wind up through the tube and causes the tube to raise in much the same way as the voltage from your battery causes the electrical current to flow along the circuits through the CPU. Wattage is simply the maximum amount of juice flowing from the battery keeping everything running at the same current.
All this nylon tube talk is only here to show you how the act of undervolting your CPU actually affects the processor itself. Yes, it does reduce stress on your CPU. Yes, it does reduce the drain on the battery. No, it will not likely produce a result that you’ve been hyped up to believe. The effects of undervolting your CPU are minimal at best, and should, in my opinion, only be used if you want your CPU to run a bit cooler under demanding tasks, such as using a heavy GPS app, like CoPilot, for a few hours, or while playing graphics intensive games for a while. Outside of that, you may gain about 30 minutes of extra run time on your battery on average (everyone’s phone is different, this is a rough average), or another couple of months of life on your CPU. Keep in mind that CPUs last many years on average under normal use, notwithstanding defects or abuse.
I’m certainly not telling you to avoid undervolting. I undervolt all my devices, including my personal computers. This post is meant to be informative since most people do this without understanding most of the concepts, while they buy into the hype generated around this. My main point is that the main reason you should undervolt is to keep the heat down on your device while you do demanding things. After all, you have a device in your hands today, most likely, that is more powerful than most desktop PCs just a few short years ago. Why wouldn’t you want to get everything out of it?
Bonus example:
Yet another example of voltage and amperage is your own cell phone charger. Most cell phone chargers now are 5V (volt), 1A (ampere/amp) chargers. This means that there are 5 volts pushing the 1 ampere electrical current to your phone over the USB cable. Wattage comes into play here in the electrical outlet. Most US electrical outlets are rated at 125 watts. Most cell phones are rated at 4-5W (watts) per hour. This means, that the outlet will still have a capacity of 120 or so watts per hour left over while your phone is charging.
How to undervolt:
The procedure for undervolting is different for each device (normally), so I’m not going to show anyone how to do it here. There are a few apps on the market that can help you do it if your kernel supports this feature. If you don’t know if your kernel supports this feature, please ask your ROM chef. Most, if not all, stock ROMs do not support this.
Apps:
The following apps will allow you to tweak your voltage settings if your kernel/ROM allow it. Root is required. There are many more on the market, but these are a few of the most popular ones.
System Tuner Pro
Set CPU
Voltage Control
IncrediControl
Reserved
Thanks for the info CFB
Sent from my GT-I9300 using Tapatalk 2
cajunflavoredbob said:
Introduction:
If you’re reading this, I’m going to assume that you want to learn something new. I love sharing knowledge with others, so I hope you do as well. With that being said, please understand that I’m doing this in my spare time, and have no degree of any kind on this topic. What I’ve compiled here is a pretty good guide to explain and hopefully educate some of you on a highly talked about, but widely misunderstood concept of CPU architecture.
Before we begin, I need to make sure you all understand a few basic concepts of electricity. I can’t teach you new material if you don’t know the language, right?
Terminology:
Voltage
The first term is, of course, voltage. Voltage is defined as the difference in electrical potential between two points. What does that mean, I’m sure you wonder? Well, to put it simply, think of a fire hydrant. When the valve is opened to let water into a hose, from the hydrant, it rushes in all at once to the end of the hose. It sits there in the hose until the nozzle is opened to put out the fire. The force that pushes the water forward is called water pressure, and like water pressure, voltage pushes the electrical current along as well. So, we will think of voltage itself as the force or pressure being applied behind an electrical current to keep it moving.
Amperage
Next up is the term, amperes. In short this is the electrical current itself. An ampere, or amp for short, is the actual unit of measurement for the amount of electricity passing a single point in a circuit at one time. This might seem confusing, so let’s just keep it simple and think of an amp as the electrical current itself. In the fire hose example, the amperage would be the water inside the hose.
Wattage
Last up is something called a watt. Now, this one can get tricky, so stick with me. A watt literally measures the rate of energy conversion or the transfer of energy. So, essentially, the watt measures the amount of work done over time. This is where it gets tricky and a little confusing. Wattage, in the fire hose example, would be the amount of water that the fire hose can hold. This is the work, or wattage, generated by the hose while operating under a constant flow of water. Now, that’s the tricky part right there. ‘Work’ in this example isn’t a normal 9-5 job. It is, more simply put, the overall capacity of the hose. A normal household lightbulb is rated around 60 watts. This means that while it’s on, it is producing a constant amount of light. This constant amount is 60 watts, which is its peak brightness under constant current.
So, to sum these three terms up as simply as possible, think of voltage as pressure, amperage as the current, and wattage as the capacity.
Example
One final example should help with this analogy. We’ve all seen those wacky waving inflatable arm flailing tubemen before, right? If not, or if you’ve never seen Family Guy before, it’s basically a long, nylon tube that is open at both ends. One end is attached to a fan at the bottom, while the other end is left open for air to escape. When the fan at the bottom is turned on, it begins to generate wind that inflates the tube and causes it to rise off the ground and flail about in the air. In this example, the voltage is the air pressure keeping the tube floating, the wind flowing through the tube is the amperage, and the amount of wind needed to make the tube rise off the ground is called the wattage.
Undervolting:
Myth or fact?
Let’s go ahead and start off with a bang, shall we? First, let me make it clear to you that no matter what people tell you, undervolting your CPU will not magically make your battery last five days longer than it should. I’m not saying it doesn’t save battery at all, because it does. It just doesn’t save as much as you’ve probably been led to believe. On any average smartphone battery under normal conditions, you should not expect an increase of more than a few percent while undervolting.
Does this mean you should stop undervolting altogether? Not at all! Quite the contrary, actually. Undervolting is actually a very good thing for your smart phone when you do it correctly. Undervolting has one major positive effect on your CPU: it will extend the life of your processor by allowing it to do demanding things with lower heat generation. In the tube example from before, undervolting would be like reducing the fan speed as low as possible while still keeping the tube in the air. The air pressure lowers along with the wind current, or amperage. Due to the now lower amount of pressure, the amount of wind being pushed through the tube (amperage, remember?) is lowered slightly as well. This, in turn, prolongs the life of the nylon tube itself by putting less strain on it while it’s flapping around in the breeze. It’s kind of like how a flag flying in the breeze will last longer than one you fly on the back of your truck while you drive down the highway.
Summary:
Now that we’ve learned all this, what does it all mean? Well, going back to the nylon tube example, the tube itself is the CPU. So, all three properties discussed before come into play here around the nylon tube (CPU). The air pressure forces the wind up through the tube and causes the tube to raise in much the same way as the voltage from your battery causes the electrical current to flow along the circuits through the CPU. Wattage is simply the maximum amount of juice flowing from the battery keeping everything running at the same current.
All this nylon tube talk is only here to show you how the act of undervolting your CPU actually affects the processor itself. Yes, it does reduce stress on your CPU. Yes, it does reduce the drain on the battery. No, it will not likely produce a result that you’ve been hyped up to believe. The effects of undervolting your CPU are minimal at best, and should, in my opinion, only be used if you want your CPU to run a bit cooler under demanding tasks, such as using a heavy GPS app, like CoPilot, for a few hours, or while playing graphics intensive games for a while. Outside of that, you may gain about 30 minutes of extra run time on your battery on average (everyone’s phone is different, this is a rough average), or another couple of months of life on your CPU. Keep in mind that CPUs last many years on average under normal use, notwithstanding defects or abuse.
I’m certainly not telling you to avoid undervolting. I undervolt all my devices, including my personal computers. This post is meant to be informative since most people do this without understanding most of the concepts, while they buy into the hype generated around this. My main point is that the main reason you should undervolt is to keep the heat down on your device while you do demanding things. After all, you have a device in your hands today, most likely, that is more powerful than most desktop PCs just a few short years ago. Why wouldn’t you want to get everything out of it?
Bonus example:
Yet another example of voltage and amperage is your own cell phone charger. Most cell phone chargers now are 5V (volt), 1A (ampere/amp) chargers. This means that there are 5 volts pushing the 1 ampere electrical current to your phone over the USB cable. Wattage comes into play here in the electrical outlet. Most US electrical outlets are rated at 125 watts. Most cell phones are rated at 4-5W (watts) per hour. This means, that the outlet will still have a capacity of 120 or so watts per hour left over while your phone is charging.
How to undervolt:
The procedure for undervolting is different for each device (normally), so I’m not going to show anyone how to do it here. There are a few apps on the market that can help you do it if your kernel supports this feature. If you don’t know if your kernel supports this feature, please ask your ROM chef. Most, if not all, stock ROMs do not support this.
Apps:
The following apps will allow you to tweak your voltage settings if your kernel/ROM allow it. Root is required. There are many more on the market, but these are a few of the most popular ones.
System Tuner Pro
Set CPU
Voltage Control
IncrediControl
Click to expand...
Click to collapse
Great post but I still have a few questions - How do we know what are safe values to undervolt to and what aren't? I'm on the HTC Mecha so my issue may be slightly different.
Klonopin said:
Great post but I still have a few questions - How do we know what are safe values to undervolt to and what aren't? I'm on the HTC Mecha so my issue may be slightly different.
Click to expand...
Click to collapse
Re-read the heading in the OP that says "How to undervolt."
Great guide for anyone wanting to learn about undervolting and CPU. So simply stated that Even an apple user could understand this. :thumbup:
AT&T SGS3
ParanoidKangDroid 1.1.0
KT747 10/28 OC'ed & UV'ed
Medical MJ Supporter
Dankest said:
Great guide for anyone wanting to learn about undervolting and CPU. So simply stated that Even an apple user could understand this. :thumbup:
AT&T SGS3
ParanoidKangDroid 1.1.0
KT747 10/28 OC'ed & UV'ed
Medical MJ Supporter
Click to expand...
Click to collapse
Aww. That's not nice. Lol
cajunflavoredbob said:
Introduction:
If you’re reading this, I’m going to assume that you want to learn something new. I love sharing knowledge with others, so I hope you do as well. With that being said, please understand that I’m doing this in my spare time, and have no degree of any kind on this topic. What I’ve compiled here is a pretty good guide to explain and hopefully educate some of you on a highly talked about, but widely misunderstood concept of CPU architecture.
Before we begin, I need to make sure you all understand a few basic concepts of electricity. I can’t teach you new material if you don’t know the language, right?
Terminology:
Voltage
The first term is, of course, voltage. Voltage is defined as the difference in electrical potential between two points. What does that mean, I’m sure you wonder? Well, to put it simply, think of a fire hydrant. When the valve is opened to let water into a hose, from the hydrant, it rushes in all at once to the end of the hose. It sits there in the hose until the nozzle is opened to put out the fire. The force that pushes the water forward is called water pressure, and like water pressure, voltage pushes the electrical current along as well. So, we will think of voltage itself as the force or pressure being applied behind an electrical current to keep it moving.
Amperage
Next up is the term, amperes. In short this is the electrical current itself. An ampere, or amp for short, is the actual unit of measurement for the amount of electricity passing a single point in a circuit at one time. This might seem confusing, so let’s just keep it simple and think of an amp as the electrical current itself. In the fire hose example, the amperage would be the water inside the hose.
Wattage
Last up is something called a watt. Now, this one can get tricky, so stick with me. A watt literally measures the rate of energy conversion or the transfer of energy. So, essentially, the watt measures the amount of work done over time. This is where it gets tricky and a little confusing. Wattage, in the fire hose example, would be the amount of water that the fire hose can hold. This is the work, or wattage, generated by the hose while operating under a constant flow of water. Now, that’s the tricky part right there. ‘Work’ in this example isn’t a normal 9-5 job. It is, more simply put, the overall capacity of the hose. A normal household lightbulb is rated around 60 watts. This means that while it’s on, it is producing a constant amount of light. This constant amount is 60 watts, which is its peak brightness under constant current.
So, to sum these three terms up as simply as possible, think of voltage as pressure, amperage as the current, and wattage as the capacity.
Example
One final example should help with this analogy. We’ve all seen those wacky waving inflatable arm flailing tubemen before, right? If not, or if you’ve never seen Family Guy before, it’s basically a long, nylon tube that is open at both ends. One end is attached to a fan at the bottom, while the other end is left open for air to escape. When the fan at the bottom is turned on, it begins to generate wind that inflates the tube and causes it to rise off the ground and flail about in the air. In this example, the voltage is the air pressure keeping the tube floating, the wind flowing through the tube is the amperage, and the amount of wind needed to make the tube rise off the ground is called the wattage.
Undervolting:
Myth or fact?
Let’s go ahead and start off with a bang, shall we? First, let me make it clear to you that no matter what people tell you, undervolting your CPU will not magically make your battery last five days longer than it should. I’m not saying it doesn’t save battery at all, because it does. It just doesn’t save as much as you’ve probably been led to believe. On any average smartphone battery under normal conditions, you should not expect an increase of more than a few percent while undervolting.
Does this mean you should stop undervolting altogether? Not at all! Quite the contrary, actually. Undervolting is actually a very good thing for your smart phone when you do it correctly. Undervolting has one major positive effect on your CPU: it will extend the life of your processor by allowing it to do demanding things with lower heat generation. In the tube example from before, undervolting would be like reducing the fan speed as low as possible while still keeping the tube in the air. The air pressure lowers along with the wind current, or amperage. Due to the now lower amount of pressure, the amount of wind being pushed through the tube (amperage, remember?) is lowered slightly as well. This, in turn, prolongs the life of the nylon tube itself by putting less strain on it while it’s flapping around in the breeze. It’s kind of like how a flag flying in the breeze will last longer than one you fly on the back of your truck while you drive down the highway.
Summary:
Now that we’ve learned all this, what does it all mean? Well, going back to the nylon tube example, the tube itself is the CPU. So, all three properties discussed before come into play here around the nylon tube (CPU). The air pressure forces the wind up through the tube and causes the tube to raise in much the same way as the voltage from your battery causes the electrical current to flow along the circuits through the CPU. Wattage is simply the maximum amount of juice flowing from the battery keeping everything running at the same current.
All this nylon tube talk is only here to show you how the act of undervolting your CPU actually affects the processor itself. Yes, it does reduce stress on your CPU. Yes, it does reduce the drain on the battery. No, it will not likely produce a result that you’ve been hyped up to believe. The effects of undervolting your CPU are minimal at best, and should, in my opinion, only be used if you want your CPU to run a bit cooler under demanding tasks, such as using a heavy GPS app, like CoPilot, for a few hours, or while playing graphics intensive games for a while. Outside of that, you may gain about 30 minutes of extra run time on your battery on average (everyone’s phone is different, this is a rough average), or another couple of months of life on your CPU. Keep in mind that CPUs last many years on average under normal use, notwithstanding defects or abuse.
I’m certainly not telling you to avoid undervolting. I undervolt all my devices, including my personal computers. This post is meant to be informative since most people do this without understanding most of the concepts, while they buy into the hype generated around this. My main point is that the main reason you should undervolt is to keep the heat down on your device while you do demanding things. After all, you have a device in your hands today, most likely, that is more powerful than most desktop PCs just a few short years ago. Why wouldn’t you want to get everything out of it?
Bonus example:
Yet another example of voltage and amperage is your own cell phone charger. Most cell phone chargers now are 5V (volt), 1A (ampere/amp) chargers. This means that there are 5 volts pushing the 1 ampere electrical current to your phone over the USB cable. Wattage comes into play here in the electrical outlet. Most US electrical outlets are rated at 125 watts. Most cell phones are rated at 4-5W (watts) per hour. This means, that the outlet will still have a capacity of 120 or so watts per hour left over while your phone is charging.
How to undervolt:
The procedure for undervolting is different for each device (normally), so I’m not going to show anyone how to do it here. There are a few apps on the market that can help you do it if your kernel supports this feature. If you don’t know if your kernel supports this feature, please ask your ROM chef. Most, if not all, stock ROMs do not support this.
Apps:
The following apps will allow you to tweak your voltage settings if your kernel/ROM allow it. Root is required. There are many more on the market, but these are a few of the most popular ones.
System Tuner Pro
Set CPU
Voltage Control
IncrediControl
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thanks for the information!!!
Good job guys. Why don't I requote the entire passage to thank the op instead of hitting the thanks button.
Sent from my GT-N7000 using Xparent ICS Tapatalk 2
hariskoirala said:
thanks for the information!!!
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Thanks for quoting a long post like a douchebag.
Markuzy said:
Good job guys. Why don't I requote the entire passage to thank the op instead of hitting the thanks button.
Sent from my GT-N7000 using Xparent ICS Tapatalk 2
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Oh, please do. You're not cool unless you do it. /sarcasm
I don't understand those guys...
cajunflavoredbob said:
Thanks for quoting a long post like a douchebag.
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He's probably post farming with useless "Thanks/me too/excellent/this is useful" posts to get the min 10 posts...
All such people should be reported.
Markuzy said:
He's probably post farming with useless "Thanks/me too/excellent/this is useful" posts to get the min 10 posts...
All such people should be reported.
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Probably so. Those guys don't understand how easy it is to make ten useful posts.
Epic thanks for the guide its pretty easy for dummies like me to follow
nikufellow said:
Epic thanks for the guide its pretty easy for dummies like me to follow
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I'm glad you enjoyed it. I was hoping to make it as simple as possible. I'm glad it worked.
Very useful info
Thanks
Sent from my ST25i using Tapatalk 2
Really informative thread. Helped clear a lot of confusions. Wish everyone explained things this nicely.
Very nice. Thanks be clicked.
WHO DAT!!
Can you please tell a rough estimate of safe range. Or is there no danger in undervolting?
Sent from my IM-A770K using xda app-developers app
When I undervolt, I do a little at a time and make sure things are stable before trying again.. Make sure u do a nandroid and if u have any trouble, you can always boot into recovery and restore if u can't change ur voltages back to where they were stable.. Just my 2¢
From my rat infested note ii