So this is a development idea...
I thought about this the other day and realized that under volting could be causing my battery to die quickly...
Here's why.
V = I * R
Where v = volts, I = amps, R = ohms.
P = V * I
Where P = (power)watts
I know some of you are going to think that this doesn't belong in development, but here me out here.
So if the processor uses 1.5 Watts and we decrease the voltage, this means that the processor needs to increase current to maintain that power. This equates to reduced battery life.
I'm just suggesting that undervolting may be causing the low battery life. If you know better feel free to tell me I'm wrong, but please explain the mechanics of what is going on not just your theory.
This question is over my head so I'll refrain from speculating directly on your theory. But real-world results with my undervolted Stupidfast 1.54 kernel gives me much better battery life than stock. Yes, this may be due also to the unbloated-ness as well so I'm not 100% certain the undervolting is the main help here
Well....I dunno how this applies to CPUs but.... I used to be a car audio installer/buff and when we noticed voltage sagging to an amplifier, the amplifier would compensate by pulling more amperage at the lower voltage. It never seemed to make much different to the batteries, but it did make the amps run much hotter...so....
Again, not sure if it would tie in, but....
Hmm I've never thought about that. From my RC knowledge the most efficient set ups are the ones that use high voltage but low amps.
I may have to try a OV kernel and see if I notice a difference...
Sent from my Samsung Fascinate running BH3.0, DL09, 125mv undervolt Voodoo5 using SwiftKey and Tapatalk
As a disclaimer, I have not performed any formal reading on this topic, these are just my idle ramblings.
My contention has been that you only enjoy the benefits of a UV kernel if you are a certain type of user.
If you are performing CPU intensive tasks, you reap the most benefit from the UV kernel because it needs less power to run at 1 GHz (or whatever the maximum clock speed is set to for that kernel).
If you spend alot of time idling, for instance reading interspersed by web requests, you are spending most of your time at the minimum clock speed. With the stock kernel, that is set to 0.1 GHz. With a UV kernel, the minimum clock needs to be set to something higher to keep the CPU running. You may be able to estimate what this speed needs to be based on the fundamental power calculations in the OP.
The governor quickly changes your clock speed based on your current usage & requirements. To make optimal use of the CPU governor, it should have access to the broadest possible range of speeds (without going higher than is useful/safe). Unfortunately, undervolting a kernel sacrifices some of the lower end of that range. Therefore, many users see much improved battery life, while others (like me) experience noticeably diminished overall performance from UV kernels.
Swyped w/ XDA App. When in doubt, mumble.
P=V*I
The processor does not draw a constant power, but it does have a minimum. The point of undervolting is bringing the power consumption to that minimum within the phones physical environment and user expectations of functionality.
So...
You are right.
However, processor frequency is dependant on current. Thus if you are undervolting to save battery life then you will need to keep your frequency the same or lower to notice a difference. If you are overclocking (increasing current) and undervolting then your P stays the same so the user ends up feeling the battery life to be the same or worse.
Facundo
Are there any standard or over volt kernels available so we can test this theory? It seems as though all the kernels available are UV.
Sent from my SCH-I500 using XDA App
would you like a standard voltage kernel to test?
Personally I see worse battery life on UV kernel. My usage mostly equals to dumb phone, with email sync and moderate web browsing.
I would change formula to I = V/R, which will read as current is directly proportional to voltage and inversely proportional to resistance. That makes obvious that reducing voltage we decrease current. However one point to note here is that this law is for PASSIVE conductor, which is obviously not our case. I would not speculate further, because we do not know what king of power conversion happens. It might simply turn out that conversion is not efficient at lower voltages. Google desktop power block certifications/efficiency to see whet I mean.
I compiled some kernels so you folks can play with it. I SERIOUSLY doubt you will get better life with my stock voltage vs. undervolt, but give her a shot.
Undervolted
Voodoo
http://adrynalyne.us/files/kernels/adryn_test2_0116_fascinate_voodoo5.zip
Nonvoodoo
http://adrynalyne.us/files/kernels/adryn_test2_0116_fascinate_novoodooo.zip
Standard voltage
Voodoo
http://adrynalyne.us/files/kernels/adryn_sv_0116_fascinate_voodoo5.zip
Nonvoodoo
http://adrynalyne.us/files/kernels/adryn_sv_0116_fascinate_novoodoo.zip
I'm giving the SV Voodoo kernel a try right now.
Sent from my Samsung Fascinate running BH3.0, DL09, and Voodoo5 using SwiftKey and Tapatalk
I thought about this as I thought about power lines. They use super high voltages to reduce the amount of power loss through the lines.
Anyways, sounds good, I'll test it out. I'd have to get a baseline. I guess I'll charge my phone right now and test out the regular voltage.
I'll let you guys know tomorrow the differences tomorrow.
In all honesty, I don't ever feel that I get more juice out of unvervolt kernels and I've been using all kinds of kernels since the release of MT3G.
Thanks for the standard voltage kernel!
I do appreciate you efforts in continually optimizing these, having a baseline to compare to just makes it all the more wonderful.
I will give the SV (standard voltage) a day or so of testing and then compare the UV against to make the test fair. With ten minutes of use ^^, it is already a great contender for my daily driver. I had gone back to 11/29 from 12/30. 11/29 was a terrible pairing with DL09; my GPS was unusable.
$ busybox md5sum ad*.zip
aea1047f3b2d33e759064d47cc8cac27 adryn_sv_0116_fascinate_novoodoo.zip
Works great!
Swyped w/ XDA App. When in doubt, mumble.
I wonder if android has battery test application, just to be put everything in the same play field? It's kind of pointless to compare subjectively.
Well, I tried to be objective with this test I just did.
Here were my conditions:
Charge to full, write down the time it was at full charge which wasn't 100%.
Let it sit for one hour.
Write down the charge.
SV Conditions
Starting charge 99%
Ending charge 97%
UV Conditions
Starting charge 98%
Ending charge 96%
The results...
SV - 3% discharge / hour
UV - 2% discharge / hour
Errors analysis:
There are several issues with this test because they were not even at the same charge at the start. Batteries have their maximum charge at 100%, and the rate of decrease is not a linear decrease. More testing is needed to compare the results.
Also the duration is not long and other factors have not been considered such as background applications refreshing on their own. I will have to test for 8-10 hours of each at idling tomorrow to get an accurate measurement.
Currently, I'm still on the UV kernel and I'll publish my results tomorrow of the UV over the 10 hour period.
Then I'll try to not use my phone throughout the day and test the SV.
It would be nice if someone could test the SV and UV with moderate usage and write down the initial charge, final charge, and the duration between the measurements. And another using heavy usage.
Thanks.
RacerXFD said:
SV Conditions
Starting charge 99%
Ending charge 97%
UV Conditions
Starting charge 98%
Ending charge 96%
The results...
SV - 3% discharge / hour
UV - 2% discharge / hour
Click to expand...
Click to collapse
Im confused with your math here...
Yeah, your math is off.....
Sent from my SCH-I500 using XDA App
RacerXFD said:
So this is a development idea...
I thought about this the other day and realized that under volting could be causing my battery to die quickly...
Here's why.
V = I * R
Where v = volts, I = amps, R = ohms.
P = V * I
Where P = (power)watts
I know some of you are going to think that this doesn't belong in development, but here me out here.
So if the processor uses 1.5 Watts and we decrease the voltage, this means that the processor needs to increase current to maintain that power. This equates to reduced battery life.
I'm just suggesting that undervolting may be causing the low battery life. If you know better feel free to tell me I'm wrong, but please explain the mechanics of what is going on not just your theory.
Click to expand...
Click to collapse
I'm an electrical engineer, and none of this makes any sense. V=IR is for current and voltage going through/across a constant resistor. Transistors are not constant resistors. The current through a Metal Oxide Semiconductor Field Effect Transistor (MOSFET), the type of transistor that is in basically all ICs, is always in positive relation to the voltage, at least for the purposes of this basic explanation. Decreasing the supply voltage, which is you can consider to be the VGS of a transistor for a simple analysis, is always going to decrease the current as well. Thus, depending on the range of operation of the MOSFET, decreasing the voltage will also decrease the current and thus power will decrease more than linearly. Less current means that the transistors will charge and discharge capacitances slower, and that's why you need voltages for higher clock speeds and overclocking IN GENERAL. Device physics is really weird.
Now, someone else was saying that maybe because you undervolt it less current goes through which means it needs to spend more time in a higher clock state. This is completely false, the current going through it has nothing to do directly with the amount of work done. Yes, you need more current for faster clock speeds, but at a given clock speed, it doesn't matter how much voltage or current there is and how fast the individual parts of the circuit work, as long as the longest delay in any part of the circuit is less than the clock rate. If it's longer than the clock period, then your circuit is no longer going to function and you'll have instability and crashes, but there is a bit of wiggle room designed into these circuits because each chip can be different. That's why you can overclock or undervolt a CPU, because obviously if it was designed to run at the fastest clock speed possible, any little variation in supply voltage, temperature, manufacturing process/lithography (which is very common) would cause your CPU to completely not function. You have to design your circuits to be tolerant of some amount of error from many sources (even cosmic radiation in some cases), otherwise it won't just be slow, it won't function at all. Logic circuits are clocked to synchronize data going through the circuit, and if the timing constraints aren't always obeyed you'll get wrong answers which would probably crash your OS. Undervolting will never cause the CPU to do less work in one clock cycle, unless you undervolt it too much, in which case things will likely blow up in your face.
Sorry for the wall of text, but hopefully this will clear up some stuff. And in the future, please stick to what you're good at and don't try to speculate things based on one formula that you heard sometime in physics while you were half asleep, or something some CSR told you to get you to shut up. Believe it or not, the people who are designing CPUs and writing/modifying kernels and operating systems actually know what they're doing and you're not going to suddenly realize that they're going about their business wrong because of something you learned in high school.
Edit: One other thing. The calculation of percentages of battery life is a bit of guesswork on the side of your phone, trying to determine via statistics what a voltage level means in terms of percentage of battery life. Battery voltages don't drop linearly as you use them, and can be affected by many things, such as whether it's plugged in to the charger in particular. That's why you see a drop immediately when you unplug your phone, and why looking at 2-3% differences is completely meaningless. The better way to test would be to actually see how long you can use it with an equal amount of work being done on each voltage, which is hard to do in real life. Too many variables are present in today's smartphones, what with background tasks and data coming and going and the like. And wireless radios are a huge battery drain, especially when you're receiving a weak signal. I would advise people to just carry a charger or usb cable with them and top up your battery when you need to rather than worry so much about small differences in battery life. You'll save on a lot of stressing .
Thanks for the explanation. I'm an aerospace engineer. I did have to take a few courses in EE, but nothing to your level. So please let me know if I'm completely off on my testing.
I am pretty sure that the Devs know what they're doing, but I was getting tired of my low battery life and I was willing to test this theory of mine out for them. Again, seriously if I am completely out of the park in terms of this testing, let me know. And I'm ok with being called stupid as long as you teach me what I did wrong...
Yea, I completely forgot how with transistors, the math regarding voltage is handled differently than through a resistor. Are you telling me that the battery life will not be different between standard voltages and under voltages?
EDIT: I understand what you're saying about lowering voltage lowers current because the current has a linear relationship with the voltage in a MOSFET chip. Thanks, I had to read that like 5 times to understand and remind myself.
This is a complete waste of my time at this point because I know what's going on, but I wish to share my results anyways...
Ok here's where I got with the testing since last night. I realize that battery life is nonlinear. But i figure this is better than nothing.
But I did complete 8 hour test of SV at idle.
Starting charge percentage 94%
Ending charge percentage 82%
Which results in 1.5%/hour discharge rate at idle.
Will do the undervolt today. I'll document that in roughly 8 hours.
Related
Well I downloaded cpu master (free) to just mess around with my photon, and come to find out, the governor for the cpu is set to performance, but gave me the option to change it to powersave, so I switch it and I'll report back to you guys and see if I've found the holy Grail to even better battery life
Sent from my MoPho using XDA App
That's awesome
Sent from my MB855 using xda premium
Wait until I or another dev gets onDemand governor enabled...
I have SetCPU, and honestly, I haven't noticed a huge difference in battery life with powersave unless I seriously scale the CPU back to like 300 mhz. Then it'll last a while, if I don't do ANYTHING with it. For example, when I'm sleeping, otherwise, it just makes the phone laggy and doesn't seem to help enough to make it worth while. Just my opinion from screwing with it.
xTMFxOffshore said:
I have SetCPU, and honestly, I haven't noticed a huge difference in battery life with powersave unless I seriously scale the CPU back to like 300 mhz. Then it'll last a while, if I don't do ANYTHING with it. For example, when I'm sleeping, otherwise, it just makes the phone laggy and doesn't seem to help enough to make it worth while. Just my opinion from screwing with it.
Click to expand...
Click to collapse
The general consensus regarding over/underclocking when I had my HTC Hero was that overclocking would save battery because you could get what you wanted done faster. If you scale the CPU back massively while it is set to sleep, however, you will save a lot of battery.
xTMFxOffshore said:
I have SetCPU, and honestly, I haven't noticed a huge difference in battery life with powersave unless I seriously scale the CPU back to like 300 mhz. Then it'll last a while, if I don't do ANYTHING with it. For example, when I'm sleeping, otherwise, it just makes the phone laggy and doesn't seem to help enough to make it worth while. Just my opinion from screwing with it.
Click to expand...
Click to collapse
well, i don't know about your phone or what else you have setup, but my phone didn't lag and it seemed to help, i currently have my evo 3d active so my photon just sits there, so i can give a good feedback of idle time, but i can tell you after switching the governor, it went down 1% in 2 hours, now i say that's an improvement, so when i get back home i'll really give you guys some feedback
P.S. with any phone i had that had a fully custom kernal, i always used conservative governor
Well, perhaps it's just the apps I have running then. As I said, when it's set to sleep, it works pretty well with the powersave mode, otherwise, doesn't seem to make any real difference. Guess it's different for everyone cause of the **** they're running on their phone.
mrinehart93 said:
The general consensus regarding over/underclocking when I had my HTC Hero was that overclocking would save battery because you could get what you wanted done faster.
Click to expand...
Click to collapse
You know, I've never bought into this argument. To me, it is like saying that if I drive 100 mph I will get there faster, so I use less gas....which we all know is not how it works.
Maybe the physics are different for processors then they are for engines, but I think there is probably a happy medium somewhere. And I have a feeling that the manufactures really take this into consideration when they develop the kernels and ROMs. However, I might be wrong.
This is by no means an effort to discourage your awesome work. Everyone gets different results, but stock always seems to have the best battery life for me once all the bloat is gone. However, custom kernels do perform better. That is the trade off, in my opinion.
my2cents said:
You know, I've never bought into this argument. To me, it is like saying that if I drive 100 mph I will get there faster, so I use less gas....which we all know is not how it works.
Maybe the physics are different for processors then they are for engines, but I think there is probably a happy medium somewhere. And I have a feeling that the manufactures really take this into consideration when they develop the kernels and ROMs. However, I might be wrong.
This is by no means an effort to discourage your awesome work. Everyone gets different results, but stock always seems to have the best battery life for me once all the bloat is gone. However, custom kernels do perform better. That is the trade off, in my opinion.
Click to expand...
Click to collapse
Lol honestly I never bought into it either. I was just posting was the other devs at the time said. Even using an OC kernel, I never overclocked my phone.
mrinehart93 said:
Lol honestly I never bought into it either. I was just posting was the other devs at the time said. Even using an OC kernel, I never overclocked my phone.
Click to expand...
Click to collapse
Interesting...I hadn't thought about using an OC kernel and underclocking it back to stock. I wonder what that does, if anything, to performance.
The other concern that I have is that overclocking typically means more heat, which means more battery use... Just figured I would throw that out there too.
well, the results are in, now granted i already had the photon of the charge for more then 24 hours, so at 1d 15hr 57m and 10s i'm at 48%, but from the time i started the cpu test, 1:30pm, it was at 68% so in 8 horus there was only a 20% drop while idle, i say that's a good score , you guys tell me otherwise
A2CKilla said:
well, the results are in, now granted i already had the photon of the charge for more then 24 hours, so at 1d 15hr 57m and 10s i'm at 48%, but from the time i started the cpu test, 1:30pm, it was at 68% so in 8 horus there was only a 20% drop while idle, i say that's a good score , you guys tell me otherwise
Click to expand...
Click to collapse
and just an update, in another 4 hours, it's only gone down 2%!!!!!! come on guys, these numbers can't lie, but remember this is idle feedback, i'll re-activate my photon at the end of the week (missing the beast!) to give more detail feedback on heavy usage and most importantly 4g!!
Development. Development. Development.
Sent from my MB855 using xda premium
Not sure if this will help but let me explain the car analogy. All motors have an effeciency range at x amount of throttle. So same cars will get better gas mileage at a higher speed vs a lower one. Its getting up to that speed where most energy is used.
So let me move this over to electronics. If you run a faster clock speed while on, your apps will open faster so that ia less on time for the screen and other processes that have to run. So using more watts for less time does not always equal more than using less watts for more time. We just need to fill in those blanks and obviously overclocking will not benefit the nook or internet reader as it eould someone who opens a lot of apps for short periods. Same is true for a gamer .
Hope that makes sense and this is all IMHO of course.
Sent from my MB855 using XDA App
scoobdude said:
Not sure if this will help but let me explain the car analogy. All motors have an effeciency range at x amount of throttle. So same cars will get better gas mileage at a higher speed vs a lower one. Its getting up to that speed where most energy is used.
So let me move this over to electronics. If you run a faster clock speed while on, your apps will open faster so that ia less on time for the screen and other processes that have to run. So using more watts for less time does not always equal more than using less watts for more time. We just need to fill in those blanks and obviously overclocking will not benefit the nook or internet reader as it eould someone who opens a lot of apps for short periods. Same is true for a gamer .
Hope that makes sense and this is all IMHO of course.
Sent from my MB855 using XDA App
Click to expand...
Click to collapse
Let me start this off by saying that I am an agricultural engineer by trade. With that said, I would agree that engines have an efficiency range. However, I would not agree that it is at x throttle. Rather, it is a x load. And most cars are designed to be at optimal load at about 60 mph (wind resist, weight, etc. play a role in this). You're right, it does require more fuel to get to that speed because the load is higher until that speed is reached. Furthermore, higher speeds (greater than 60 mph) do NOT translate into higher fuel mileages because the load increases to maintain the higher speed (because there is more wind resistance, among other things).
I know a bit about electricity too, but I don't fully understand the physics behind circuit boards. However, I think the analogy still holds. I can get to 60 mph as fast as I want, but the faster I do it the more energy is required. Therefore, even though it is done faster it still requires more energy, which also creates more heat, both of which use the battery. So, I continue to contend that there is a happy medium that most be found and I think electronic engineers aren't to far off.
Here is a little more reading about car efficiency, if you are interested: http://www.mpgforspeed.com/
I believe your confusing overclocking and overvolting. We are putting x volts into the processor so the more cycles we can get in x volts the better. If we have to overvolt to overclock then we see big battery hits.
Sent from my MB855 using Tapatalk
2cents, that link is interesting but real world examples have proven otherwise to me. Our saab will do better on mpg at 70 to 75 (30 on cruise control) vs 55 to 65(27 to 28 on cruise). Now the wrx is another story as well. With the old 3.9 final drive i would pull in more air at the airflow meter at 65 than i would at 70 with stoich as the target a/f ratio, and because that motor was doing under 2500 rpms the turbo was out of the equation further taking out efficiency with it. Now with the 4.44 and a better 1-2 gear ratio car gets better at the lower engine speeds and accelerates even better and that was before i retuned it.
Another misconception is bigger motors use more gas, one of the recent corvettes get 30 on the highway proving that there is more to this as well.
I think i have taken this off topic enoigh for now. But in general i think my formula still needs to be applied to see the results as a valid number to compare overclocking and underclocking to running stock.
Sent from my MB855 using XDA App
i'm surprised no one even thought of this topic, regardless if things are getting done "faster" you are overclocking the cpu, making it go faster then what it's suppose to, which makes it use more power i.e. more battery, every phone that i had when i overclocked it, the battery wouldn't last too long, even with my 3500mah OG evo, if i overclocked it, i couldn't get a whole day, so underclocking will have the same effect in a sense since the processor now has to work harder to do what it does at it's stock clocked speed, well, hope anything i said here makes any logical sense, but on another note, the photon has gone almost 3 days unplugged!!!
again it depends on how the overclock is achieved. In most cases overclock is achieved by dumping more electricity into the cpu this will impact battery life, however alot of chips these days can be overclocked at the same volts essentially upping the "MPG" or clocks per volt.
A2CKilla said:
i'm surprised no one even thought of this topic, regardless if things are getting done "faster" you are overclocking the cpu, making it go faster then what it's suppose to, which makes it use more power i.e. more battery, every phone that i had when i overclocked it, the battery wouldn't last too long, even with my 3500mah OG evo, if i overclocked it, i couldn't get a whole day, so underclocking will have the same effect in a sense since the processor now has to work harder to do what it does at it's stock clocked speed, well, hope anything i said here makes any logical sense, but on another note, the photon has gone almost 3 days unplugged!!!
Click to expand...
Click to collapse
I agree with this for the most part. When it comes to power the end result is watts, which is essentially equal to volts x amps. It is not perfect because of a power factor, but it is close. Therefore, if you lower the voltage, the amperage goes up because the same watts are required to run the processor. The inverse is also true. These processors have voltage ranges that they will safely run in, but in the end, they require the same energy (in watts) to function at a given load. Change one a little bit (the voltage for example) and the other (amperage) compensates. Change it a lot and it likely wont work. Again, this is how it works for your typical home appliances. For a circuit board, it might be a slightly different story, but I imagine the science does not change.
---------- Post added at 03:57 PM ---------- Previous post was at 03:47 PM ----------
scoobdude said:
2cents, that link is interesting but real world examples have proven otherwise to me. Our saab will do better on mpg at 70 to 75 (30 on cruise control) vs 55 to 65(27 to 28 on cruise). Now the wrx is another story as well. With the old 3.9 final drive i would pull in more air at the airflow meter at 65 than i would at 70 with stoich as the target a/f ratio, and because that motor was doing under 2500 rpms the turbo was out of the equation further taking out efficiency with it. Now with the 4.44 and a better 1-2 gear ratio car gets better at the lower engine speeds and accelerates even better and that was before i retuned it.
Another misconception is bigger motors use more gas, one of the recent corvettes get 30 on the highway proving that there is more to this as well.
I think i have taken this off topic enoigh for now. But in general i think my formula still needs to be applied to see the results as a valid number to compare overclocking and underclocking to running stock.
Sent from my MB855 using XDA App
Click to expand...
Click to collapse
You may be right. Perhaps Saab designed their fuel efficiency at 70 mph. It's possible because many speed limits are now at or near that, but in general, optimal fuel consumption is going to be at or near 60 mph. Obviously gear ratios and such play a huge role in fuel economy. It is like using a custom rom, typically your mods will make it perform better, but the best fuel economy or battery life will come with a stock like setup.
Sure a corvette can have HP and economy. There is a power to weight ratio and lots of aerodynamics involved, which again is designed at a specific speed. But there is no way that a dragster will have a good fuel efficiency. To my point, there is a balance...
I agree, we are off topic a little bit, but the conversation is interesting, nonetheless.
By the way, can a mod move this to general, please?
Hello,
It's a well know 'fact' that our P500 draws the same amount of power when clocked at anything below 480MHz, so underclocking it below 480MHz brings no battery benefits.
I have been trying to find the reason for this, but I can't find the thread / post in the search that details the reasons for this and how it was tested. My guess is that it's buried in one of the many bloated development threads... If someone can point me in the right direction that would be great.
Cheers!
I know this thread has a quote of this post and that this is a well known information but, besides this community common knowledge (by which I'm very grateful), I also can't find any specific data on this matter.
I even found this thread that aks the same thing, but it has no answers.
So it would be great if someone could give us a bit more information about this.
Thanks in advance!
480MHz and below use the same voltage. It takes more battery to jump from say 245 to the max freq
InfiniteRisen said:
480MHz and below use the same voltage. It takes more battery to jump from say 245 to the max freq
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Click to collapse
Yes, we all 'know' this but where did this information come from?
This post shows that it is a general MSM7x27 'feature' that all frequencies below 600MHz use the same voltage. This is where we assume this to mean that it uses the exact same amount of power whether it is running at 122, 245, 320 or 480MHz, so we're taking a speed hit for no power benefit.
Does anyone knows of any benchmark tests to confirm this? I might try some tests this week, set the min/max MHz to the same value and run a program to keep the CPU at 100% and see how long it takes to drain the battery (perhaps a huge pi calculation or something).
Which do you value more, source of information or proof now?
InfiniteRisen said:
Which do you value more, source of information or proof now?
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Click to collapse
Surely that's the same thing, a good source should also contain proof of the claims it is making...
I'm not saying it's wrong, but if nobody has tested it we can't be sure, right?
adfad666 said:
Surely that's the same thing, a good source should also contain proof of the claims it is making...
I'm not saying it's wrong, but if nobody has tested it we can't be sure, right?
Click to expand...
Click to collapse
On my personal experience, i would actually say 245mhz consume less battery than 480mhz. But I still prefer the latter as it's a bit more speedy. On battery life, it's just a <1% difference between the two.
as far as what ihve read!!people say it takes infact more power consumption when we underclock very low frequencies like 122 ,since it takes more work for the phone to operate in a laggy state with very less cpu frquency ..and thats the reason i think(not sure) why we are asked to have a minimum of 480mhz frequency though i prefer 320
Test setup suggestion:
Test 1 = Idle
Set to 480/480 set to airplane mode overnight and look at battery drain.
Do the same for 245/245
Compare results
Test 2 = Intermittent load
Set to 480/729- test using on/off series of tests not 100% all the time. You want the governor to scale frequently during the test
Same test above but @ 122/729
Compare results
This will give you 2 conclusions
1 - 480 at idle does/doesn't drain battery as much as 245
2 - Increased scaling does/doesn't increase drain battery.
The longer the phone is awake the more it drains battery. Also take note of how long it takes to complete test 2.
**EDIT**
Intel has done extensive laboratory testing showing the results of Speedstep and the results carry over to ARM and governor scaling.
I'm inclined to follow the crowd on this one, no increase in voltage = no increase in power draw. That's scientific fact.
Increase in frequency will increase heat. Unnecessary scaling will also increase heat. Increased heat leads to shorter battery life, consequently overtime the battery can't hold as much of a charge. So again, nothing decisive here to make me change my mind.
If you still want to, then proceed with the tests above.
As far as I've seen, Everybody in this forum says that clocks 480 or below have the same voltage, so setting min clock as 480 is enough and no difference in terms of battery consuming even if you set it to 245.
I know it is right about voltage(I searched about that myself), but does same voltage means same energy consumption?
you guys must already know that higher clock makes more heat, so where does the heat come from? it's from your battery!
(from what I learned from school E=V^2*t/R where E is energy, V is voltage, t is time and R is resistance so there's another fact for electric energy other than voltage and time)
So I think you should set the min freq to 245 unless you feel uncomfortable for its low responsiveness.
is there anything wrong in my theory?
For this you can't depend on equations etc, it has to be tested each by everyone of us to feel which one is better for us and which is more battery saving. Personally I felt 245mhz drains a bit less than 480mhz however it is less responsive. I remember i saw in forums about this(althought another device) and it was one heck of a debate, but the conclusion was each and every person has to test for themselves.
And the wakes ofcourse, the amount the kernel wakes per second.
Deep sleep **** counts also...
If you have wakelocks, set as low as you can, if you don't, use 480
Sent from my LG-P500
You're right about energy consumption,i've been with extreme-cpu overclocking(on pc) for quite some time and a higher clock on same voltage will indeed consume more+more heat. But here like you've seen ^ it's related to wakelocks and if there are any apps running, if deep sleep is ok and stuff so there are many factors.
Best is to try and see wich fits you best regarding performance/battery/stability also it depends on the guvernor if you have a snappy one it will push your cpu to max even if you surf between screens
This is one of the biggest "not solved point" about O.1 configuration....
To adress this and other "open point" i developed an app for logging resources consumption
more info here:http://forum.xda-developers.com/showthread.php?t=1505950
Did a test with a cpu benchmark (simple thing to test how fast it does some things)
Did those in powersave governor:
122MHz
>10000ms (took a minute to do the test)
480MHz
~1900ms
Also did in 245, and I got 4392ms, and this is very good
Sent from my LG-P500
If someone would teach me that would be great!
Sent from my SAMSUNG-SGH-I717 using xda app-developers app
Better battery life. But be careful with undervolting. It can cause phone to be unstable. Under clocking is more forgiving. If you are going to do either I would suggest only making small changes and then use phone for several hours to settle in. If all good then try next step lower and test until you find the limit of your phone. Then bump it back up to last stable setting.
There are no noticeable benefits.
jimmer411 said:
There are no noticeable benefits.
Click to expand...
Click to collapse
I agree, its mostly the placebo effect regarding lag, a variable effect regarding battery life, due to user apps, and downright dangerous regarding overheating.
But many people whine when its not available for a kernel. I don't have a very high opinion of its necessity.
Battery life in our phones is dominated by the screen and radio (cell and wifi) but I find that undervolting at least reduces the heat when I'm doing something intensive like SNES emulation. Lag in our phones is also primarily a software issue (I have other Android devices with the same hardware running at the same MHz and it's a smoother experience).
Not that my Note got hot, it's just less warm.
ZacksBuilds said:
If someone would teach me that would be great!
Sent from my SAMSUNG-SGH-I717 using xda app-developers app
Click to expand...
Click to collapse
There's no reason not to under volt.
UC=Under clock
UV=Under volt
OC=Over clock
OV=Over volt.
Newer generations of chips have tremendous tolerances. If you were to look at the S3, a Qualcomm built SoC that was a bit long-in-the-tooth by the time the Note was released, you'd see that in many cases, there were phones that featured the chip, but were clocked lower... I.E at 1,000 MHz.
Most chips are designed to run faster than they do, at least for short periods of time. Modern chips use temperature and load to designate the running frequency.
When Qualcomm releases a chip, they need to be sure that 99% of the units they produce, can run with a near-flawless level of stability. Because of this, they often run chips slower, and at a higher voltage than is actually needed. The result is, that Qualcomm or Samsung might design a chip rated for 2ghz, and release their first device with the chip running at 1.5ghz. This is common. Each piece of silicon is slightly different due to manufacturing differences. Chips are made on giant discs, with hundreds of chips on a single disc. The chips in the center are generally considered to be of a slightly higher quality, requiring less voltage, or capable of running at a higher frequency, sometimes both. Because of this, each device is capable of slightly more, or slightly less. The challenge is for Qualcomm to set the speed and power usage for every chip-- the challenge for us, is to see if we can run the chip at a higher frequency, while drawing less power....because power =heat, and power= battery life.
There are two different ways to approach customizing frequency and voltage to your needs.
One: If you could run your Note at 1,900mhz, instead of 1500mhz, and draw the same amount of power, that'd be considered a success case. Your device would be faster, without a hit in battery life.
Two: Or, if you could run the device at the same speed, and lower the voltage (saving battery life), this would also be considered a success.
Sometimes, but rarely in the mobile space, you'll get lucky and receive a prime piece of silicon, and you'll be able to over clock, WHILE undervolting...resulting in a faster phone that uses battery life.
Ranger was correct...clock speed changes on the order of +/-20 percent are hardly noticeable. However, power requirements grow exponentially at higher frequencies, and on a mobile device, they're noticeable. While a device might require 1.2 volts at 1.5 GHz, and 1.3 at 1.6ghz, it might also only require 1.05, or 1.0 volts at 1.4ghz. These numbers are theoretical, and shouldn't be used-they arent even close to correct. They're used merely to illustrate that to over clock, chips often require more power than over clocking is worth, in heat (and heat past a certain point will instantly fry your device, or will reduce the lifespan of the chip).
These are general ideas on over clocking. If you want to know something specific, ask away. When over clocking/underclocking, the governor used (a set of conditions that tells the CPU when to change from, say 300mhz (when the screen is off, and the device isn't being used), to 1.5ghz, when both cores are being used, and fully loaded.
If you want to save battery life, a combination of build.prop radio tweaks, modem tweaks, under clocking profiles, and using a custom governor can significantly increase standby time, and noticeably, but not too significantly increase usage time. Its important to know though, that the screen is the hungriest part of our device, and brightness is the the quickest setting to adjust to gain battery life.
The same is true for performance. Kernel, OC profiles, build.prop and launcher tweaks, GOU over clocking, etc. All in combination can have a noticeable effect, because performance is the net sum of dozens of moving parts.
Sent from my SGH-I717 using XDA Premium HD app
Jamesyboy said:
There's no reason not to under volt.
UC=Under clock
UV=Under volt
OC=Over clock
OV=Over volt.
Newer generations of chips have tremendous tolerances. If you were to look at the S3, a Qualcomm built SoC that was a bit long-in-the-tooth by the time the Note was released, you'd see that in many cases, there were phones that featured the chip, but were clocked lower... I.E at 1,000 MHz.
Most chips are designed to run faster than they do, at least for short periods of time. Modern chips use temperature and load to designate the running frequency.
When Qualcomm releases a chip, they need to be sure that 99% of the units they produce, can run with a near-flawless level of stability. Because of this, they often run chips slower, and at a higher voltage than is actually needed. The result is, that Qualcomm or Samsung might design a chip rated for 2ghz, and release their first device with the chip running at 1.5ghz. This is common. Each piece of silicon is slightly different due to manufacturing differences. Chips are made on giant discs, with hundreds of chips on a single disc. The chips in the center are generally considered to be of a slightly higher quality, requiring less voltage, or capable of running at a higher frequency, sometimes both. Because of this, each device is capable of slightly more, or slightly less. The challenge is for Qualcomm to set the speed and power usage for every chip-- the challenge for us, is to see if we can run the chip at a higher frequency, while drawing less power....because power =heat, and power= battery life.
There are two different ways to approach customizing frequency and voltage to your needs.
One: If you could run your Note at 1,900mhz, instead of 1500mhz, and draw the same amount of power, that'd be considered a success case. Your device would be faster, without a hit in battery life.
Two: Or, if you could run the device at the same speed, and lower the voltage (saving battery life), this would also be considered a success.
Sometimes, but rarely in the mobile space, you'll get lucky and receive a prime piece of silicon, and you'll be able to over clock, WHILE undervolting...resulting in a faster phone that uses battery life.
Ranger was correct...clock speed changes on the order of +/-20 percent are hardly noticeable. However, power requirements grow exponentially at higher frequencies, and on a mobile device, they're noticeable. While a device might require 1.2 volts at 1.5 GHz, and 1.3 at 1.6ghz, it might also only require 1.05, or 1.0 volts at 1.4ghz. These numbers are theoretical, and shouldn't be used-they arent even close to correct. They're used merely to illustrate that to over clock, chips often require more power than over clocking is worth, in heat (and heat past a certain point will instantly fry your device, or will reduce the lifespan of the chip).
These are general ideas on over clocking. If you want to know something specific, ask away. When over clocking/underclocking, the governor used (a set of conditions that tells the CPU when to change from, say 300mhz (when the screen is off, and the device isn't being used), to 1.5ghz, when both cores are being used, and fully loaded.
If you want to save battery life, a combination of build.prop radio tweaks, modem tweaks, under clocking profiles, and using a custom governor can significantly increase standby time, and noticeably, but not too significantly increase usage time. Its important to know though, that the screen is the hungriest part of our device, and brightness is the the quickest setting to adjust to gain battery life.
The same is true for performance. Kernel, OC profiles, build.prop and launcher tweaks, GOU over clocking, etc. All in combination can have a noticeable effect, because performance is the net sum of dozens of moving parts.
Sent from my SGH-I717 using XDA Premium HD app
Click to expand...
Click to collapse
So what I understood is this: instead of having let's say, your note running at 1.2ghz consuming 15% battery per hour you can have it at 1.5ghz consuming the same battery life?
Sent from my SAMSUNG-SGH-I717 using xda app-developers app
Hello Axon 7 users, I just picked up one a couple of days ago. After finally figuring out the bootloader, bootstack and general stock experience I tested a little bit of gaming. I found that a basic game like Clash Royale heats the battery up to around 42°C already with low brightness and slow charging. A more intensive game like the new Knives Out runs only slightly hotter but it becomes apparent that CPU gets throttled soon after loading to 1036MHz across all cores causing lag.
It's disappointing so I tried to find how to modify the throttling. Using ZTE's Power Manager setting on performance or balanced doesn't seem to have a noticeable difference.I tried the only stock custom kernel AX7 but it's outdated on B32 and I find it randomly reboots regularly. The stock kernel itself allows some configuration, but the thermal settings in Kernel Adiutor don't reflect any charge.
A quick Google search brings up how LG V20 Snapdragon 820 users edit /system/etc/thermal-engine.conf to tweak the throttling levels. Their config is quite different but they mod big to 1824Mhz and let little scale itself.
I couldn't get thermal-engine.conf to use the thermal-engine-8996-perf.conf values by copying the values to it as it suggests inside. I tried renaming it with the -zte.conf ending as it suggests as well but that didn't work. After just renaming both the normal and perf conf files with a .bak ending, I've found better throttling performance. Big now throttles to 1632Mhz and little to 1324Mhz. As far as I can understand the files don't have charging rates inside, just GPU and CPU throttling.
However as expected the device heats up a few degrees more now. This now puts my battery up to 47°C in Knives Out under the same conditions. Charging is stopped at 45°C by the system so as previously mentioned it's unmodified.
I just wanted to check since I couldn't find it mentioned. Is everyone ok with gaming performance limited to 1036Mhz with the normal throttle? Also are my temperatures normal? I guess CPU doesn't seem that high reaching around 65°C, it's just that the battery has less than 20°C difference in intensive performance. I suppose it's a quirk of the heat pipe to battery as heatsink design. I just expected more from a metal unibody chassis and at least normal CPU gaming performance. I thought my Sony Z3 Compact design was bad for battery thermals, with the battery stacked behind the CPU board, sandwiched in insulating glass. But I didn't expect to see a phone to route a heatpipe directly to it's battery.
Anyway it is what it is. Follow this information if you want some better gaming performance at the cost of your battery cycle life. In my case I bought the Axon7 just as a separate media consumption device rather than a phone so I can live with the tradeoff. If battery gets bad enough before 2 years I'll consider using warranty at the loss of receiving their refurbished replacement. Manufacturer warranty's in fact cover batteries for 80% depletion.
I recommend the app DevCheck Pro for being able to monitor CPU, GPU, temperatures and other things overlayed. I think some others may do similar but they may not be updated for Big Little and are more instrusively overlayed.
Infy_AsiX said:
A quick Google search brings up how LG V20 Snapdragon 820 users edit /system/etc/thermal-engine.conf to tweak the throttling levels. Their config is quite different but they mod big to 1824Mhz and let little scale itself.
I couldn't get thermal-engine.conf to use the thermal-engine-8996-perf.conf values by copying the values to it as it suggests inside. I tried renaming it with the -zte.conf ending as it suggests as well but that didn't work. After just renaming both the normal and perf conf files with a .bak ending, I've found better throttling performance. Big now throttles to 1632Mhz and little to 1324Mhz. As far as I can understand the files don't have charging rates inside, just GPU and CPU throttling.
Click to expand...
Click to collapse
I read half of that to be honest, but just one thing: To make things harder, ZTE added added a write protection on the system. To disable it you have to use a computer and connect your phone with ADB, then issue "adb reboot disemmcwp" (like DISable EMMC Write Protection). Otherwise all the changes that you made get undone after a reboot, and obviously you'd have to reboot after modifying that file
On LOS you can use BeastMode (even if your phone isn't an A2017U) which for me is the best friggin kernel I've used in performance terms. There you can change thermal limits
Infy_AsiX said:
Hello Axon 7 users, I just picked up one a couple of days ago. After finally figuring out the bootloader, bootstack and general stock experience I tested a little bit of gaming. I found that a basic game like Clash Royale heats the battery up to around 42°C already with low brightness and slow charging. A more intensive game like the new Knives Out runs only slightly hotter but it becomes apparent that CPU gets throttled soon after loading to 1036MHz across all cores causing lag.
It's disappointing so I tried to find how to modify the throttling. Using ZTE's Power Manager setting on performance or balanced doesn't seem to have a noticeable difference.I tried the only stock custom kernel AX7 but it's outdated on B32 and I find it randomly reboots regularly. The stock kernel itself allows some configuration, but the thermal settings in Kernel Adiutor don't reflect any charge.
A quick Google search brings up how LG V20 Snapdragon 820 users edit /system/etc/thermal-engine.conf to tweak the throttling levels. Their config is quite different but they mod big to 1824Mhz and let little scale itself.
I couldn't get thermal-engine.conf to use the thermal-engine-8996-perf.conf values by copying the values to it as it suggests inside. I tried renaming it with the -zte.conf ending as it suggests as well but that didn't work. After just renaming both the normal and perf conf files with a .bak ending, I've found better throttling performance. Big now throttles to 1632Mhz and little to 1324Mhz. As far as I can understand the files don't have charging rates inside, just GPU and CPU throttling.
However as expected the device heats up a few degrees more now. This now puts my battery up to 47°C in Knives Out under the same conditions. Charging is stopped at 45°C by the system so as previously mentioned it's unmodified.
I just wanted to check since I couldn't find it mentioned. Is everyone ok with gaming performance limited to 1036Mhz with the normal throttle? Also are my temperatures normal? I guess CPU doesn't seem that high reaching around 65°C, it's just that the battery has less than 20°C difference in intensive performance. I suppose it's a quirk of the heat pipe to battery as heatsink design. I just expected more from a metal unibody chassis and at least normal CPU gaming performance. I thought my Sony Z3 Compact design was bad for battery thermals, with the battery stacked behind the CPU board, sandwiched in insulating glass. But I didn't expect to see a phone to route a heatpipe directly to it's battery.
Anyway it is what it is. Follow this information if you want some better gaming performance at the cost of your battery cycle life. In my case I bought the Axon7 just as a separate media consumption device rather than a phone so I can live with the tradeoff. If battery gets bad enough before 2 years I'll consider using warranty at the loss of receiving their refurbished replacement. Manufacturer warranty's in fact cover batteries for 80% depletion.
I recommend the app DevCheck Pro for being able to monitor CPU, GPU, temperatures and other things overlayed. I think some others may do similar but they may not be updated for Big Little and are more instrusively overlayed.
Click to expand...
Click to collapse
I have noticed the same performance many months ago.
I tried changing the thermal values with both ways through the conf file or a custom kernel but all implementations seem to be faulty as nothing changed.
In the end I gave up because I couldn't find a solution for this.
But I figured because my games clash of clans, ppsspp, gba emulators don't lag I din't care much.
If you find a solution let me/us know.
Or post the modded confs you're using as well if you can.
That's all from me.
I just renamed both the thermal-engine files with a .bak extension. I've also got ZTE's Power Manager frozen as the performance profiles there don't seem to do anything and I don't use it's other features. There's some kind of CPU GPU throttle still in place but it's much higher as previously mentioned,. After searching further I saw your discussion about /vendor/bin related throttle, maybe that's the fallback it's now on.
The device does get uncomfortably hot with a new demanding game at maximum settings. I wouldn't recommend doing this if you want to maintain your battery. However if you're interested I discovered the Ax7 allows defining a lower maximum battery voltage in another TL/DR post https://forum.xda-developers.com/showpost.php?p=74746734&postcount=1353. To explain simply, it's possible to limit the voltage low for health and safety while keeping the device almost primarily powered by mains. Effectively the battery is at an optimum low voltage, practically idle but very hot. A little complicated sure, but worth it. Getting a Daydream V1 tomorrow to play with, this stuff will help with heat and performance a lot. If anyone wants my long winded explanation, give me a shout.
The CPU temp does jump around higher than 70. I'm tending to think that current powerful mobile processors aren't efficient enough for the physical body constraints of phones. Let alone poorly designed ones. The 820 is meant to be an improvement over the 810, wouldn't believe it by the throttle required and performance lost. The 835 is efficient enough apparently. From experience though I have my doubts on reviews and benchmarks to reflect real usage stress.
edit: Oh and disable VDD restriction in your kernel setting if you've set it to auto enable. That seems to be a switch for the aggressive throttle still available after mod.
Sent from my ZTE Axon 7 using XDA Labs
Infy_AsiX said:
I just renamed both the thermal-engine files with a .bak extension. I've also got ZTE's Power Manager frozen as the performance profiles there don't seem to do anything and I don't use it's other features. There's some kind of CPU GPU throttle still in place but it's much higher as previously mentioned,. After searching further I saw your discussion about /vendor/bin related throttle, maybe that's the fallback it's now on.
The device does get uncomfortably hot with a new demanding game at maximum settings. I wouldn't recommend doing this if you want to maintain your battery. However if you're interested I discovered the Ax7 allows defining a lower maximum battery voltage in another TL/DR post https://forum.xda-developers.com/showpost.php?p=74746734&postcount=1353. To explain simply, it's possible to limit the voltage low for health and safety while keeping the device almost primarily powered by mains. Effectively the battery is at an optimum low voltage, practically idle but very hot. A little complicated sure, but worth it. Getting a Daydream V1 tomorrow to play with, this stuff will help with heat and performance a lot. If anyone wants my long winded explanation, give me a shout.
The CPU temp does jump around higher than 70. I'm tending to think that current powerful mobile processors aren't efficient enough for the physical body constraints of phones. Let alone poorly designed ones. The 820 is meant to be an improvement over the 810, wouldn't believe it by the throttle required and performance lost. The 835 is efficient enough apparently. From experience though I have my doubts on reviews and benchmarks to reflect real usage stress.
edit: Oh and disable VDD restriction in your kernel setting if you've set it to auto enable. That seems to be a switch for the aggressive throttle still available after mod.
Click to expand...
Click to collapse
That's weird... what are the ambient temps where you live? Here it's anything between 20 and 30 degrees and mine never gets that hot, and it barely throttles. Of course you shouldn't game while charging, that WILL throttle the phone.
I have a big old CPU heatsink without a fan, and when I charge the phone at night I just put it upon the heatsink. It keeps the battery around the ambient temp, which I guess helps with battery degradation.
A nice app for monitoring the CPU is Trepn profiler, you can program it to show you anything like frequencies and temps on 2 separate graphs for example