Related
I haven't been able to find any info on undervolting the Xoom, so have started this thread in the hope that some may find it beneficial.
What is undervolting?
It basically involves reducing the amount of electrical voltage running through the CPU. It does not affect the speed of the CPU at all, just the amount of power that it uses. The stock configuration of CPUs usually has a fairly high voltage, to cater for the fact that CPUs are not exactly identical.
Why undervolt?
Reduce power consumption, and therefore increase battery life.
Why not undervolt?
Can affect stability, and there is a small risk of damage to your device.
Disclaimer: Undervolting, like overclocking, does have the potential to damage your device. It's very rare, but not unheard of. I've never had a problem, but you may. Good luck, and don't blame me.
My config:
Model: MZ601 Xoom
Kernel: Tiamat Xoom v2.1.0
Undervolting software: SetCPU 2.2.4
My voltages before UV:
MHz mV
216 770
312 770
456 825
608 900
760 975
816 1000
912 1050
1000 1100
1200 1150
1408 1250
1504 1325
1600 1400
1704 1400
So after doing a bit of testing, I've found that I can lower my voltages noticeably throughout the range, reducing the amount of power my Xoom uses, and prolonging my battery.
My UV voltages:
MHz mV
216 770
312 770
456 775
608 825
760 875
816 925
912 975
1000 1000
1200 1075
1408 1125
1504 1175
1600 1250
1704 1325
Notes:
It is not possible to UV any less than 770 mV (with the kernel I'm using anyway).
Given that the mV for the 456 CPU frequency is so similar to 216, I set my minimum clock frequency to 456, which makes the device more responsive.
So, you may want to try these voltages, and see how they work for you.
To test: (Instructions for SetCPU)
Set your min & max speeds to the same frequency, for example 456.
Set the voltage of the 456 frequency to an amount lower that the current amount, for example 775. (It's generally best to adjust your voltage down only 25mv at a time.)
Perform a "Stress Test", for at least about 5 seconds.
If the device locks up or reboots, the mV is too low - try a higher mV.
Once you've found the optimal voltage for that frequency, move onto the next one, for example 608, then 760, etc.
If your device locks up or freezes during testing, you can force a reboot by holding down the Volume Up button, and the Power button.
The voltages I've used above may work for you, or you may have to increase them a little on your device. You may also get better voltages than me - if so, please post your results.
Battery test results
Performed some battery performance testing by doing the following steps:
1. Set the screen to not turn off, and brightness to 10% (screen needs to be on to keep the stress test running, and brightness low to minimise the battery drain of the screen, as that's not what we're testing).
2. Disabled all network connections (WiFi, Bluetooth, Data, GPS) to minimise battery drain by other factors.
3. Closed all other apps, and did not use the Xoom at all during the tests.
4. Charged Xoom to 100%.
5. Set CPU speed to 1504mhz using SetCPU (both min & max frequencies the same for accurate testing).
6. Unplugged the Xoom.
7. Ran "Stress Test" for 2 hours (give or take 20 seconds).
I performed the above steps for both stock voltage, and undervolted voltage. Results as follows:
1. For stock voltage (1325mV on Tiamit Tachi kernel), battery life went down to 62%.
2. For undervolted voltage (1175mV, which is nice & stable for me), battery life went down to 72%.
Findings:
I was expecting battery savings, but not quite this much.
Standard voltage (at 1504mhz) at this CPU load, drains at about 19% per hour.
UV voltage at this CPU load, drains at about 14% per hour.
Standard voltage at this CPU load, the Xoom would drain battery entirely after about 5.26 hours.
UV voltage at this CPU load, the Xoom would drain battery entirely after about 7.14 hours.
In addition to the battery savings, the Xoom was only slightly warm after the UV tests, but very warm after the standard voltage tests. (Standard voltage test was performed first.)
Note: For general usage (email, browsing, basic apps & widgets), the CPU is not as heavily used. But in situations where the CPU is heavily used (such as intensive games), these results show there is significant potential for battery savings.
super nice tips. Tq very much
126-608 -175
Others -150
This is my settings... no prob at all.
Would I use setcpu app or just use the Moray(in settings) or does it matter
rayhodge02 said:
Would I use setcpu app or just use the Moray(in settings) or does it matter
Click to expand...
Click to collapse
Not sure what the "Moray" is, but any tool capable of undervolting should be ok. I like and use SetCPU, but I've tried other tools on other devices in the past, and they did similar things.
nobody wants to share their result after trying?
Very good job, I try
Sent from my Xoom using xda premium
pls share ur best result
I try your results and they're unstable in function off the useful task, exemple impossible to play simple games.
That's all right just for basic tasks like navigation, music ...
Sent from my Xoom using xda premium
Hmm, your stress testing seems inaccurate.
I used your values and did a stress test at each frequency for around 10 seconds. No problem. But my xoom restarted just 5 mins later while I was surfing the net.
So I increased each frequency by 25-50 and it stayed stable since then.
for me i just underclock my xoom to 912mhz. it is almost as fast as 1ghz. and i save battery alot.
Gregus59 said:
I try your results and they're unstable in function off the useful task, exemple impossible to play simple games.
That's all right just for basic tasks like navigation, music ...
Sent from my Xoom using xda premium
Click to expand...
Click to collapse
Try bumping up the voltages a little bit at a time, until you find a stable setting. The settings I listed are what are stable for my Xoom (even intensive 3D games), but CPUs vary. What I get, others may not, and others may get better than me.
musashiken said:
Hmm, your stress testing seems inaccurate.
I used your values and did a stress test at each frequency for around 10 seconds. No problem. But my xoom restarted just 5 mins later while I was surfing the net.
So I increased each frequency by 25-50 and it stayed stable since then.
Click to expand...
Click to collapse
They're not 100%. The longer you stress test, the more likely the CPU is stable, but 10 seconds gives a general idea. If unstable, just do as you did, and increase by 25mv or so.
omnia1994 said:
126-608 -175
Others -150
This is my settings... no prob at all.
Click to expand...
Click to collapse
Can you confirm your mV values? -175 sounds like a big saving. Surely your mV is not less than the minimum 770?
What kernel are you using?
do some proper tests to establish how much extra time you will get from a fully charged batt.
i would think its perhaps a tiny bit at most...
the screen would take a huge amount of the batt, the processor would use only a small percentage, so surely cutting a small fraction off a couple of steppings is fairly pointless?
baron von bubba said:
do some proper tests to establish how much extra time you will get from a fully charged batt.
i would think its perhaps a tiny bit at most...
the screen would take a huge amount of the batt, the processor would use only a small percentage, so surely cutting a small fraction off a couple of steppings is fairly pointless?
Click to expand...
Click to collapse
1. It depends what you're using the device for. Games, for example, can use a lot of CPU, so undervolting in this instance, will definitely use noticeably less battery.
2. If CPU voltage throughput didn't make any difference, we'd all just run our devices at 1700mhz all the time.
3. With undervolting, I can run my Xoom at the same voltage at 456mhz, as it run at 216mhz. This means I set my minimum frequency to 456 instead, and for the same minimum battery consumption, my device is noticeably smoother.
If you want to know how much extra time you will get from a fully charged battery, YOU do some tests.
lindsaytheflint said:
Can you confirm your mV values? -175 sounds like a big saving. Surely your mV is not less than the minimum 770?
What kernel are you using?
Click to expand...
Click to collapse
Yes i m sure. Has been using these settings till now.. no prob at all. Using tiamat stock gpu kernal with moray rom
i agree that during low intensity operation the power savings are probably nearly negligible, but during CPU-intense usage it could save a bit.
I myself am not willing to leave my Xoom on full bore for a series of tests lasting 7-10 hours each just to quantify how much power undervolting can save under super extraordinary circumstances.
But even if the energy savings is an arguable benefit, the reduction in CPU temperature is not. That alone makes this worth doing, IMO.
Agree.. after setting it my xoom now has lower temp when playing it
Caveats: Every CPU and GPU does not come from the same bin, fabricated on the same date and possibly not manufactured in the same facility. They may each display different physical properties and a wider range of stability than others. What works for me may not work for you.
That being said, I've been stress testing my device with different settings for the past couple weeks trying to find a sweet spot of stability, speed, battery life and heat output.
I'm going to share two setups: my current one that I've stress tested for less than 24hrs but has proved stable through all conditions encountered thus far and my tried and true setup I've used for over a week with no trouble.
Tried and true setup:
Governor - ondemand
Range - 100MHz through 1.6GHz
100MHz - 800mV
200MHz - 825mV
300MHz - 850mV
400MHz - 900mV
500MHz - 900mV
600MHz - 900mV
700MHz - 925mV
800MHz - 950mV
900MHz - 1000mV
1000MHz - 1025mV
1100MHz - 1100mV
1200MHz - 1125mV
1300MHz - 1150mV
1400MHz - 1175mV
1500MHz - 1250mV
1600MHz - 1350mV
Experimental but stable battery saver:
Governor - ondemand
Range - 100MHz through 1.6GHz
100MHz - 775mV
200MHz - 775mV
300MHz - 800mV
400MHz - 800mV
500MHz - 825mV
600MHz - 850mV
700MHz - 875mV
800MHz - 900mV
900MHz - 950mV
1000MHz - 1000mV
1100MHz - 1100mV
1200MHz - 1125mV
1300MHz - 1150mV
1400MHz - 1175mV
1500MHz - 1225mV
1600MHz - 1350mV
GPU setup:
Low power state - 100MHz @ 800mV
High performance state - 400MHz @ 1050mV
Notes:
Custom governors were not stable for me AT ALL! I've found ondemand to be the best one for me and my needs, personally.
100MHz @ 750mV was so, SO close to being stable for me but my phone would routinely reboot in the screen off state. I'm assuming the stress of apps updating in the background, notifications etc was just too much.
As much as I love WidgetLocker (and I really do!), I found it to consume valuable resources, have more pronounced wake up lag and generally contribute to instability.
I use Chainfire3D to run my games etc. at x4 MSAA. As previously stated by Chainfire, the Mali can run at x4 with almost no extra overhead. I imagine that if one doesn't use x4 MSAA, one *might* be able to get away with 400MHz @ the stock 1000mV setting. That being said, I consider an extra 50mV to run at 133MHz faster to be a bargain.
Many games can be run with x16 MSAA with minimal overhead but I've found that for some resource intensive ones, especially multiplayer, they'll slow down unless the GPU is fed at 1200mV but this in turn causes a lot of heat generated so I would advise to avoid turning on x16 MSAA for those that you do find slowing down.
I use and recommend Voltage Control (donate version for extra features!) for setting up clock range and voltage for both the CPU and GPU. It also allows one to set boot settings (at setup or init.d script) and create multiple profiles. I do not recommend init.d script for untested settings as it could cause you issues.
Edit: Not everyone's kernels may support GPU OC/UV or the CPU ranges listed here. I am not responsible if you bork your device.
Here's someone else's method for testing settings:
Here's how I test UV settings.
Turn on everything. Wifi, bluetooth, max brightness, the whole works. This ensures the system is at maximum strain.
Start at maximum CPU clock
Lock the CPU clock (set the minimum and maximum allowed clock to the clock you are currently undervolting)
Lower the voltage by one step
Start a benchmark for a few minutes to see if undervolted clock is stable
If it passes, lower it again go back to step 4
When it freezes up your phone, reboot it and increase the voltage at that clock by two steps and consider it safe
Move to next frequency and go back to step 3.
You reached your lowest clock? Congrats, you should have a well undervolted CPU
Your voltages should always be lowering when your go from the highest clock to the lowest. If it happens that you have to increase the voltage at a lower clock, then also increase the higher clock frequency. I had a few hard locks because of this.
Example.
1000mAh (1GHz) > 900 mAh (900MHz) *< 950 mAh (800MHz) * > 700mAh (600mAh)
The 800MHz voltage is now higher than the 900MHz voltage. Also increase the 900MHz voltage to the same or higher voltage of the lower one.
1000mAh (1GHz) > 950 mAh (900MHz) > 950 mAh (800MHz) > 700mAh (600mAh)
Now that you have it undervolted, you may find that it could hardlock/reboot on you. When it happens do this:
Increase the voltage on all undervolted clocks by one step.
Continue using the device for a day
If the device locks up again, go back to back step 1
If its ok for a day, then every day lower the voltage back to what you had of only one clock (I suggest you go from highest to lowest)
You should be able to find which undervolt caused the reboot fairly quickly and still be able to normally use the phone and keep the rest of the "optimal" undervolts.
Click to expand...
Click to collapse
Sent from my GT-N7000 using xda premium
I don't think UV saves battery. It is display that sucks most of the juice.
You save less than 2% with extreme UV and after a single reboot caused by instability - you lose even more battery.
There's an excellent thread in Nexus S forums - "battery drain benchmarks" (please search it).
I had similar UV settings and my phone never crashed during benchmarks or stress tests.
But it always crashed while installing 100+ apps with app backup restore, restoring backups with TB or MBR, gaming.
After removing UV, it never crashed.
I haven't tested UV with ICS... would see and report if it really saves battery.
Boy124 said:
I don't think UV saves battery. It is display that sucks most of the juice.
You save less than 2% with extreme UV and after a single reboot caused by instability - you lose even more battery.
There's an excellent thread in Nexus S forums - "battery drain benchmarks" (please search it).
I had similar UV settings and my phone never crashed during benchmarks or stress tests.
But it always crashed while installing 100+ apps with app backup restore, restoring backups with TB or MBR, gaming.
After removing UV, it never crashed.
I haven't tested UV with ICS... would see and report if it really saves battery.
Click to expand...
Click to collapse
I'm not sure if you've read everything through carefully or you would have seen that I've covered several of your points.
You also would have seen the method I use for stress testing and would have noted that I aim for four things: speed/performance, stability, power management AND thermal regulation.
While I agree that the display, barring a wonky or misbehaving app, will almost always be the #1 battery drainer - power management will certainly help to conserve battery life.
You also would have seen I mention profiles. There may not be a one size fits all setting for everyone but one can most certainly set up profiles for different scenarios.. Such as TiB backups/restores.
Sent from my GT-N7000 using xda premium
Did you do some benchmarks at the highest speed several times to make sure you are getting extra performance? With this phone I noticed that while the phone wont crash.. .some times performance will drop when running at settings now fully correct.
Sent from my GT-N7000 using XDA
You covered a lot of points but UV is total waste of time.
You get nothing out of it.
http://forum.xda-developers.com/showthread.php?t=1478406
Could you please post your data, how much battery do you save after UV?
Disagree boy, cause with wakelock screen is off, there is significant battery drain, I went to 10 hours life on single charge, due to wakelock.
Normally with deepsleep about 2 days. That's a reduction of 87.5% with screen off. Cpu running @200mhz.
Do the same with undervolting will dramatically increase battery life in that situation. So overal it will be a fraction compared to using the device with screen on, but still significant.
Edit: guess I was wrong here
Sent from my GT-N7000 using Tapatalk 2
baz77 said:
Disagree boy, cause with wakelock screen is off, there is significant battery drain, I went to 10 hours life on single charge, due to wakelock.
Normally with deepsleep about 2 days. That's a reduction of 87.5% with screen off. Cpu running @200mhz.
Do the same with undervolting will dramatically increase battery life in that situation. So overal it will be a fraction compared to using the device with screen on, but still significant.
Sent from my GT-N7000 using Tapatalk 2
Click to expand...
Click to collapse
I actually did the test on Gingerbread.
I set min and max to 200 MHz, activated flight mode and had stock music player running for 3 hours - with undervolt and without undervolt.
To my surprise battery consumption was the same.
May be experts who know about our processor architecture can shed some light here.
Boy124 said:
You covered a lot of points but UV is total waste of time.
You get nothing out of it.
http://forum.xda-developers.com/showthread.php?t=1478406
Could you please post your data, how much battery do you save after UV?
Click to expand...
Click to collapse
I understand where you're coming from, boy.
I don't have data at the moment though I wish I did. But to be honest, it'd be scrambled anyway since whenever I'm not working or mission critical when I need proven stability, I'm testing out all different sorts of settings leading to lots and LOTS of reboots and such!
That being said, anecdotally, I have seen improved battery life for myself but maybe it's a placebo and I could be wrong about it - I have been before in the past. I do feel though that under my normal usage scenarios, I am experiencing less battery drain. It's difficult to quantify though exactly what this is due to since I experiment with kernels, voltages and frequencies.
But if all I'm getting is a 2% boost, man - I'll take it! Like any modder, whether it's min/maxing in a game, working on a car or whatever else, every little bit of a parameter squeezed out is something.
I also feel that you're too caught up on a single aspect, the battery life thing, to the detriment of my overarching holistic goal - efficiency.
Originally I started undervolting and experimenting with frequencies because of thermal output. I had wanted to experiment with x16 MSAA settings, which led to my GPU needing 400MHz and 1200mV which led to lots of heating up which led to me experimenting with everything I could.
Efficiency is what I want. The best performance at the best speeds at the best battery life at the best thermal regulation I can manage.
Now I'm looking at energy efficiency. I'm seeing suggestions that 100MHz may not be as efficient as 200MHz on our Exynos because the tradeoff in frequency power usage isn't worth the longer time spent completing tasks. I'm also seeing that in some situations, a performance best governor targeting max freq may be efficient because less time is spent completing a task and a quicker return to sleep.
I'm just sharing what I'm doing and hopefully others can benefit.
http://forum.xda-developers.com/showthread.php?t=1369817
Sent from my GT-N7000 using xda premium
Wow, thats illogical makes me wonder the math behind it.
Sent from my GT-N7000 using Tapatalk 2
While I appreciate the effort thrown into this, I humbly acknowledge the conclusion is incorrect.
When you lower Voltage slightly, without affecting stability, you pretty much put a toll on the processor for extra "wear and tear" and reduce its lifespan. However, this comes at the reward of reduced current.
So, it should be saving you battery. Underclocking it (safely) is also going to save you battery. And the same thing with different governors, like interactivX compared to regular ondemand, by finishing off processes quicker and reducing the frequency and voltage quicker, and going into Deep Sleep quicker.
I don't have the means to run a Scientific Experiment to prove these claims, nor the time to conduct them. But the majority of "hackers" synonymously agree it saves a noticeable power. These include themers, kernel developers and the casual user. I don't think an educated MAJORITY can be incorrect to the scale of this test's claims.
Im looking for someone to tell me what they think is there best settings to be used in there prefered app for example setcpu,faux123, do you overclock and to what settings, what has worked for you guys
i generally dont use my phone to much in a day so battery last the day so i dont mind it being overclocked when im using it if it means it runs faster but drains battery, some suggestion please, im a novice
no flames about i used the word 'best' im looking for opionons thankyou if you help
Whelan189 said:
Im looking for someone to tell me what they think is there best settings to be used in there prefered app for example setcpu,faux123, do you overclock and to what settings, what has worked for you guys
i generally dont use my phone to much in a day so battery last the day so i dont mind it being overclocked when im using it if it means it runs faster but drains battery, some suggestion please, im a novice
no flames about i used the word 'best' im looking for opionons thankyou if you help
Click to expand...
Click to collapse
IMO, no overclock is required. The phone is fast and snappy enough.
That said, I underclock the minimum frequency and undervolt throughout the frequency table.
This ensures that I get better battery life, without any decrease in performance.
I'm running CyanogenMod 10.1.0 Stable Release.
I'm using franco.kernel r161, and his companion app - franco.kernel updater.
The following settings are giving me great performance and battery life.
CPU Frequency Range : Screen On - 384 MHz - 1512 MHz, Screen Off - 384 MHz
CPU Governor : Interactive
GPU Frequency: 400 MHz
Frequency Table Undervolt : -125 mV throughout
Disclaimer - This is for a {fast} binned CPU. Check your device's CPU binning via this link, and do some trial-error to find the perfect undervolt for your device.
Good Luck!
I have been experimenting with some various governors and have found that interactive and ondemand work best on the nexus 7. My question is which one will have better battery life on the nexus 7? Which one will have the least stuttering? Just curious. Everyone seems to state that interactive will be the better governor, but I tend to notice interactive heats up more in chrome. Anyone else notice this?
Any helps would be appreciated
-Fishwithadeagle
When running low on battery I found conservative with runnable works the best for me. Undervolting by 50-100mV and running custom kernel plus ROM can also contribute. I always turn my WiFi and GPS off when not being used. I would not know of such imperceivable details between Interactive and Ondemand as battery, stutter or heat. Mine reaches 70 degress celsius under overclocked heavy benchmarking load.
For battery life, stick with interactive or conservative.
For less lag and stuttering, use ondemand or performance.
Sent from my Nexus 4 using Tapatalk 2
Wow, you couldn't be more wrong. You have it completely opposite. For better battery life, and not to have your frequency set to the highest value, almost at all times, go with ondemand. If you want less lag, and stuttering, but worse battery life, interactive.
Test it yourself with setcpu, and CPU spy, and you'll see exactly what I'm talking about.
The Best CPU Governor for Performance and also Battery life seems to be Interactive or Intellidemand.
For indepth Kernel Benchmarks and CPU Governor tests go to my thread here: http://forum.xda-developers.com/showthread.php?t=2625656
Here are SunSpider 1.0.2 benchmarks to prove the point.
(Lower is better)
ondemand: 1,200ms
intellidemand: 540ms
interactive: 520ms
conservative: 650ms
iPhone 5s:450ms
Conclusion: It is amazing that with this phone we can achieve performance that is close to the 64bit processor of the iPhone 5S. Screw Apple. (Just Kidding) Interactive is the best CPU governor. The end.
Lastly, you may wonder why I only posted Sunspider Benchmark results because that is only a javascript test and doesn't prove how the kernel will perform overall. First of all let me state that those numbers are after extensive testing under numerous different Stock and KitKat roms and Kernel combinations. Secondly, in terms of AnTuTu and Quadrant scores, you can expect them to be the same across all the CPU governors above. But the sunspider can be helpful in gauging browser performance. And since most users browse the web on their smartphones, it is wise to switch away from the default ondemand or ondemanplus which is a much more conservative version of ondemand, and instead use intellidemand or interactive or conservative.
It is interesting that conservative provides good performance and sunspider results. Maybe if you really want to be sure you have good battery life, you should stick with conservative. Although in all honesty, battery life is dependent on your brightness, and subsequently amount of screen on time, and then of course, the amount of CPU intensive tasks you perform like gaming, or Web Browsing. So differences between governors and battery life will be minimal if you do not adjust your user behavior...
I'm using a LS980 Sprint LG G2. I suspect that across variants results should be the same since SoC are based on the Snapdragon 800.
Conservative micro stuttered too much for my liking. Stuck to interactive.