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Anybody notice one performing better than the other with regard to battery life? I have the paid version of SetCPU which I bought for my G1 a while back but I'm not sure I really need it for the CPU throttling on the Vibrant but it does seem to improve battery life and I was wondering if Juice Defender might be better.
JuiceDefender was fabulous for battery life but it did slow down my phone a lot. I ended up uninstalling it. If you want to try toggling your data to save battery, I recommend DCSwitch widget. Works like a charm for data control.
I just started using SetCPU on this phone so I can't say how it affects battery.
Tasker is better then Juice Defender. It does everything JD does and MUCH more stuff.....unlimited possibilities
You should probably understand that lowering the frequency of your processor doesn't save a bit of battery. The only way you can save battery is to lower the voltage which neither of those apps can do so whatever you're seeing as "saving battery" is a placebo effect. When the phone is in sleep mode the CPU is defaulted at 245mhz. Lowering the "Max" frequency does just that; it lowers the maximum frequency the processor is able to use.
bmj1086 said:
You should probably understand that lowering the frequency of your processor doesn't save a bit of battery. The only way you can save battery is to lower the voltage which neither of those apps can do so whatever you're seeing as "saving battery" is a placebo effect. When the phone is in sleep mode the CPU is defaulted at 245mhz. Lowering the "Max" frequency does just that; it lowers the maximum frequency the processor is able to use.
Click to expand...
Click to collapse
It's true that reducing voltage (which we can't do) would be more effective as power consumption at a given clock frequency is proportional to the square of the voltage, but you're wrong to dismiss frequency control as a power saving strategy because at any given voltage, power consumption is proportional to frequency. Hence Intel's "speed step" technology used in notebook CPU's.
Juice Defender and SetCPU are doing more or less the same thing as Intel speed step.
We CAN reduce voltages with the right kernel... Dragon TEST 5 kernel.
^ correct with the voltage control app from the market i believe.
Between setCPU and juice defender..
i say juice defender.
Set CPU is a hassle.
It shuts your phone off sometimes with profiles on, and freezes it etc.
If your phone experiences any of those problems, uninstall setcpu and bam, your phone is normal again.
SetCPU is only good for overclocking, and sometimes sucks at that too.
xriderx66 said:
^ correct with the voltage control app from the market i believe.
Between setCPU and juice defender..
i say juice defender.
Set CPU is a hassle.
It shuts your phone off sometimes with profiles on, and freezes it etc.
If your phone experiences any of those problems, uninstall setcpu and bam, your phone is normal again.
SetCPU is only good for overclocking, and sometimes sucks at that too.
Click to expand...
Click to collapse
Yeah, that's what happened to me with setcpu. Every time the screen turned off, the phone turned off as well.
With juice defender, I lost a lot more battery. About 15% in 3 hrs of standby vs. 3-4% in 3 hrs of standby without any power saving apps.
If people are having good results with both apps, could you please show how you set it up? I may have not set it up right.
burntrat said:
With juice defender, I lost a lot more battery. About 15% in 3 hrs of standby vs. 3-4% in 3 hrs of standby without any power saving apps.
If people are having good results with both apps, could you please show how you set it up? I may have not set it up right.
Click to expand...
Click to collapse
Same here.
I figured that people who got positive results from all the battery-saving apps are the ones that use their phones aggressively and switching between all types of connections (wifi/bluetooth/gps). I use my phone normal, so I'm better off without apps like that.
Yeah, that's what happened to me with setcpu. Every time the screen turned off, the phone turned off as well.
Click to expand...
Click to collapse
If I remembered correctly, it's because you've set the frequencies way too low for your phone to function properly.
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.
I've install Rom Toolbox,
and i saw there is a "CPU slider" where i control the clock speed.
i've put it to 1000MHz instead of 1200MHz and tested it for several days
i really dont feel any difference in performance.
browsing seems same, games like asphalt is equally smooth.
heating is similar, equally warm.
the only difference is quadrant benchmark.
1200MHz scores 3200-3400
1000MHz scores 2600-2900
frankly speaking, i'm not sure if there's any difference in battery life.
is there any way to accurately test whether the clock speed affects the battery life?
i've seen other threads, where there are very different opinions.
some say it will improve battery life, and some say its worst.
http://forum.xda-developers.com/showthread.php?t=726019
Quote: (SetCPU doesn't make a difference in battery life, it can only shorten it. The kernal already has the best settings for CPU speed built in.)
http://forum.xda-developers.com/showthread.php?t=1305465
Quote: (if you are able to stand the side effects of underclocking, it will surely boost your batery life.)
On my SGS2 program called CpuSpy shows that 1200MHz is about 1% of total cpu time (remember that governor is ondemand and CPU is at 1200 only when need it). If power consumption is directly proportional to clock speed by limiting it to 1000MHz you will get about 20% less power usage by 1% of time... looks like 0.2% power saved ? Soo if Your phone works for about 48h on one charging this way You can get about 6 extra minutes. It's just my guess...
Also have to consider if slower cpu causes screen to eat power for longer time... (because You have to wait longer for operation to complete)
slig said:
On my SGS2 program called CpuSpy shows that 1200MHz is about 1% of total cpu time (remember that governor is ondemand and CPU is at 1200 only when need it).
If power consumption is directly proportional to clock speed by limiting it to 1000MHz you will get about 20% less power usage by 1% of time... looks like 0.2% power saved ? Soo if Your phone works for about 48h on one charging this way You can get about 6 extra minutes. It's just my guess...
Also have to consider if slower cpu causes screen to eat power for longer time... (because You have to wait longer for operation to complete)
Click to expand...
Click to collapse
HI, thanks for replying. I understand what you mean. the phone dont operate at 1200MHz all the time. but when using browser, and playing games, such as asphalt, it runs at max CPU usage almost the entire gaming duration.
Anyway.....
the real question is whether the clock speed is directly proportional to the battery consumption.
while reading your post, i thought of a brilliant ideal how to verify this.
the CPU slider not only allows you to set the max CPU speed,
you can set the min CPU speed as well.
So, i thought of an experiment, lets set the min & max CPU to 1200MHz,
this way, the phone will be running constantly at max CPU even when its idle.
let the phone be turn on till it run out of battery, record the time, T1.
then repeat again with max and min CPU set to 1000MHz.
record the time it is turn on till it run out of battery, record time as T2,
then compare T1 & T2, this could certainly work.
it would be nice if any member here happens to have 2 sgs2, and tried them ;-)
There are two more things to consider
1. CPU is not the only element that consumes power.
2. SGS2's Exynos is always clocked at 200MHz when the screen is off - check if this minimum slider affects that too.
Please let know how your experiment goes.
Regards
when the screen is off, the phone will be in "deep sleep" state. i think thats less than 200MHz.
anyway, i wont be doin this experiment any time soon.
you see, this is my only phone, i need to use it.
i dont have much oportunity to leave it and wait for it to run out of juice.
still, i'll try it when i have the chance.
First of all, I am totally new to this forum.(I mean as an registered user)
Before that I always had the thing from the forum what I needed.
Now here is my question,
If i overclock the processor speed of my android device to a higher position, isn't it gonna take more battery power than usual?
Phone model: Xperia Live With Walkman
Boot loader: unlocked
Root Access: Rooted
Kernel: Rage 3.2
ROM: Real ICS r6
overclocking is going to drain your battery obviously.
overclocking drains more battery but gives better performance,too much over clocking makes phone heat & even hardware issues
saqib nazm said:
overclocking drains more battery but gives better performance,too much over clocking makes phone heat & even hardware issues
Click to expand...
Click to collapse
My phn's original capacity is 1 Ghz
How much overclocking can keep my battery level fair and also give smoother performance without causing me any hardware issue?
Btw, Thx for the ans.:good:
Saimoon said:
My phn's original capacity is 1 Ghz
How much overclocking can keep my battery level fair and also give smoother performance without causing me any hardware issue?
Btw, Thx for the ans.:good:
Click to expand...
Click to collapse
Power consumption = Voltage x Voltage x cpufreq x some constant for your device. If you OC (raise the cpufreq) you will have more power consumption and more heat generation because most of the power is dissipated as heat and the heat is what damages your cpu. It is probably impossible to kill your cpu in one go, because your device should shut off when it begins to over heat (this will look like a random reboot). But you will slowly degrade the over all performance of your cpu and eventually you get to a point where you see a lot of random reboots. So if you decide to OC you probably want to also undervolt as well. This is because power consumption (and heat) scale with the square of the applied voltage. One rule of thumb is that your maximum cpufreq is actually determined by the voltage. For example, my cpu is rated to be stable at 1 GHZ and 1200 mV, so when I OC and UV, I scale the cpufreq as high as I can go, as long as the voltage is not greater than 1200 mV, for me this is 1.5 GHz.
Also remember that your cpu governor will have a big effect on your power consumption and it is probably doing a good job keeping the cpu running in the low range of the cpufreq table, so you are unlikely to see big effects of OC or UV on real life battery consumption.
every chipset is different, even though the brand and model is the same. noone can guarantee you any safe value to overclock.
Thanks Giving!
Thanks Everybody for helping me out!
I am applying 1.402 GHz :laugh:
Overclocking is not the only thing you have to think of in order to improve your phone's overall performance. The most important issue for me is choosing the right kernel and applying the right governor + I/O scheduler. From my experience with Mini (i have tried ALL available kernels and most of ROMs) I can surely say that now with my phone (ICS .587, custom ROM + kernel) overclocked to 1.5 GHz battery with minimal use (20 mins calls, 40 mins WiFi per day) lasts at least 60 hours. When I bought my phone (GB, no OC, all stock) battery was struggling to stay alive for 24 hours with the same minimal use. Conclusion: first pick the right kernel and ROM, then OC.
Just want to know everyones opinion on if it can really save life for the S4. Cause the way I see it is if the cpu is constantly being clocked down/up for instance, when my screen is off I have it so that cpu is at about 400mhz and when the screen comes on it boosts back up to anywhere between 1200 and max
If you're driving, and you slow when down to say 30mph and slam on the gas to get up to 100mph instead of steadily getting there, you're going to use a lot more gas. So if it is the same with the phone, aren't I using more battery life than saving?
Markymarc206 said:
Just want to know everyones opinion on if it can really save life for the S4. Cause the way I see it is if the cpu is constantly being clocked down/up for instance, when my screen is off I have it so that cpu is at about 400mhz and when the screen comes on it boosts back up to anywhere between 1200 and max
If you're driving, and you slow when down to say 30mph and slam on the gas to get up to 100mph instead of steadily getting there, you're going to use a lot more gas. So if it is the same with the phone, aren't I using more battery life than saving?
Click to expand...
Click to collapse
I'm not entirely sure, but with your example, doesn't that depend how long you're going 30 or how long your screen is off at a crack? If you turn on your screen for 10 minutes for every 20 it's off, I think it would save your battery more in the long run.
You use more gas in the car analogy as you have to overcome a ton or so of mass driving at 30 mph. Changing clock speeds faces no such resistance, so it won't be the same with the phone.
yes, the acceleration doesn't really affect the drain. the fact you're running at a higher clock speed is the drain. you can adjust your steps and max speed, thus saving a little bit of battery. undervolting can help to, but the cpu usually draws so little power that the savings may go unnoticed.