# Undervolting...placebo or not?



## dpaine88 (Jul 21, 2011)

So for a while I was just letting LeanKernel do its thing and use SmartReflex to calibrate my voltages.

Then I said what the hell, I'll try out UV. I am using some pretty aggresive values (LT Aggresive preset) but honeslty I don't see much of a difference in battery life or anything.

Does UV actually truely make a difference?


----------



## YankInDaSouth (Jun 9, 2011)

I thought I remembered reading (In Imo's thread maybe) that undervolting will not result in better battery.

Honestly, I don't know too much about undervolting (never cared to look into it either lol) so I am unsure of the pros and cons of it. I just let the devs do their thing and roll with it. 

Sent from my Galaxy Nexus using Tapatalk 2


----------



## g00s3y (Jul 12, 2011)

Just undervolting only will only result in, if any, very minimal battery life improvement.


----------



## dpaine88 (Jul 21, 2011)

g00s3y said:


> Just undervolting only will only result in, if any, very minimal battery life improvement.


What exactly do you mean "just undervolting only" what else would I do in conjunction with it?


----------



## russphil (Feb 28, 2012)

dpaine88 said:


> What exactly do you mean "just undervolting only" what else would I do in conjunction with it?


Underclocking. Which seems to do more for battery life than undervolting imo


----------



## dpaine88 (Jul 21, 2011)

russphil said:


> Underclocking. Which seems to do more for battery life than undervolting imo


How low are you going? Right now I am running 350-1200


----------



## russphil (Feb 28, 2012)

dpaine88 said:


> How low are you going? Right now I am running 350-1200


Sent from my Galaxy Nexus using RootzWiki


----------



## russphil (Feb 28, 2012)

dpaine88 said:


> How low are you going? Right now I am running 350-1200


384-1036 on Franco's kernel


----------



## garyd9 (Apr 9, 2012)

Unless you disable various forms of SmartReflex, I'm not sure that undervolting (or overvolting) will have much of an impact. The kernel (SR1.5) and/or the chip itself (SR3) will readjust the voltages on its own.


----------



## throwbot (Jan 2, 2012)

Man I'm not a believer in undervolting. I leave voltages stock; I think underclocking does more for battery than undervolting. With undervolting, I usually wind up with sod's eventually and the diff in battery life is negligible.

Sent from my Galaxy Nexus


----------



## nocoast (Oct 17, 2011)

Uhh....if your drawing less power your drawing less power...imoseyon wouldn't UV his kernel preset if it had no advantage...

Sent from my Galaxy Nexus using Tapatalk 2


----------



## Burncycle (Aug 6, 2011)

nocoast said:


> Uhh....if your drawing less power your drawing less power...imoseyon wouldn't UV his kernel preset if it had no advantage...
> 
> Sent from my Galaxy Nexus using Tapatalk 2


Pretty sure he has stock voltages with the option to under volt...

Undervolting is snake oil if I've ever seen it.

Sent from my Galaxy Nexus using Tapatalk 2


----------



## blaineevans (Jul 11, 2011)

Burncycle said:


> Pretty sure he has stock voltages with the option to under volt...
> 
> Undervolting is snake oil if I've ever seen it.
> 
> Sent from my Galaxy Nexus using Tapatalk 2


He doesn't use stock voltages?

"Undervolted by default (1.35ghz/1325, 1.2ghz/1300, 920mhz/1250, 700mhz/1150, 350mhz/950)

Recommend UV voltages for exp builds (won't work for everyone): 180/230/820mV, 350/840mV, 700/1010mV, 920/1080mV, 1200/1210mV, 1350/1220mV, 1520/1320mV, 1650/1420mV"

Sent from my Galaxy Nexus using Tapatalk 2


----------



## dpaine88 (Jul 21, 2011)

Burncycle said:


> Pretty sure he has stock voltages with the option to under volt...
> 
> Undervolting is snake oil if I've ever seen it.
> 
> Sent from my Galaxy Nexus using Tapatalk 2


His kernel actually does come pre-UV from the official stock values.


----------



## Burncycle (Aug 6, 2011)

blaineevans said:


> He doesn't use stock voltages?
> 
> "Undervolted by default (1.35ghz/1325, 1.2ghz/1300, 920mhz/1250, 700mhz/1150, 350mhz/950)
> 
> ...


My bad.I must have been reading something different by accident.

Sent from my Galaxy Nexus using Tapatalk 2


----------



## ERIFNOMI (Jun 30, 2011)

You're drawing less current but it's not a whole lot less. So yes, you're being easier on your battery, but not by a drastic amount. And when you use a kernel with SmartReflex, you're just setting the minimum that it can drop down to. It may draw a bit more if it needs to.


----------



## nocoast (Oct 17, 2011)

I undervolt aggressively and see pretty noticeable battery life gains...

Sent from my Galaxy Nexus using Tapatalk 2


----------



## Metallice (Jan 27, 2012)

ERIFNOMI said:


> You're drawing less current but it's not a whole lot less. So yes, you're being easier on your battery, but not by a drastic amount. And when you use a kernel with SmartReflex, you're just setting the minimum that it can drop down to. It may draw a bit more if it needs to.


You're setting the starting point not the minimum. It will start at your set voltage and move down from there.

Also with this screen undervolting won't do much. Maybe 2% if your lucky. ( On nexus S it was calculated at about 2% and that doesn't have as many pixels).


----------



## Mikefrostlpn (Jun 7, 2011)

nocoast said:


> I undervolt aggressively and see pretty noticeable battery life gains...
> 
> Sent from my Galaxy Nexus using Tapatalk 2


THIS. I have taken undervolting to the extreme. Spending hours narrowing down how low I can go without impacting performance or stability and I can get 10 hours out of my nexus at -120dbm


----------



## ERIFNOMI (Jun 30, 2011)

Metallice said:


> You're setting the starting point not the minimum. It will start at your set voltage and move down from there.
> 
> Also with this screen undervolting won't do much. Maybe 2% if your lucky. ( On nexus S it was calculated at about 2% and that doesn't have as many pixels).


Are you sure? I thought I read imo saying that it was the minimum. Then again, I don't waste my time undervolting.


----------



## Ianxcom (Jun 29, 2011)

I find that if I'm on 4g its not as noticeable since lte is such a strong drain. I notice it when on 3g mostly.

Sent from my Galaxy Nexus using Tapatalk 2


----------



## throwbot (Jan 2, 2012)

nocoast said:


> I undervolt aggressively and see pretty noticeable battery life gains...
> 
> Sent from my Galaxy Nexus using Tapatalk 2


This coming from the guy who owns thirty batteries, nyuck nyuck.

Seriously tho, I mean I'm not saying undervolting doesn't do anything, I just think that the kernel devs test that kind of thing enough for me to leave it alone. Like I said, I get way better results from under clocking as opposed to under volting. I mean, when the screen takes up 75% of your battery usage, the easiest way to increase you battery is obviously going to have to deal with it. Battery life in general is one thing, but what most people want is screen- on time. Honestly, that screen is gonna use as much juice as it needs; I've never noticed undervolting having given me longer times in that department.

On a side note, you can look at every screen shot I've ever posted-- I literally can't even get a single bar of service in my house (but it is connected at -120) at all times, so my phone is constantly searching for signal. Its the one thing that affects my battery that I really just can't do anything about.

Sent from my Galaxy Nexus


----------



## nocoast (Oct 17, 2011)

Please tell me you have lte toggled off then...

Sent from my Galaxy Nexus using Tapatalk 2


----------



## dpaine88 (Jul 21, 2011)

I went to the horses mouth on this one and asked Imoseyon, my fav kernel dev about it.

He has recommended UV values in the OP of his kernel thread which are the same as Jakes Preset UV in LeanTweaks.

I asked him if UVing had a decent impact on battery and his response was


> [background=rgb(246, 246, 246)]only to a certain extent. Going lower than recommended will probably not help a whole lot.[/background]


For me, the recommended are barely lower than what SR chooses for me.

Here are IMO's recommeneded

[background=rgb(245, 245, 245)] 180/230/820mV, [/background]
[background=rgb(245, 245, 245)]350/840mV, [/background]
[background=rgb(245, 245, 245)]700/1010mV, [/background]
[background=rgb(245, 245, 245)]920/1080mV, [/background]
[background=rgb(245, 245, 245)]1200/1210mV, [/background]
[background=rgb(245, 245, 245)]1350/1220mV, [/background]
[background=rgb(245, 245, 245)]1520/1320mV, [/background]
[background=rgb(245, 245, 245)]1650/1420mV[/background]


----------



## TEK112 (Dec 22, 2011)

My thoughts are that no amount of undervolting will ever come close to offsetting the screen and LTE. We are talking 1-2 percentage points an hour with regular underclocking. For stability I don't try to push it. I like not having SODs and the occasional 5 second wait to wake the device or the inherent race to idle issues. If that means losing 10% over the course of a normal charge I am OK with that. The devs do a tremendous job UV from the stock values, going lower seems more like a self fulfilling adventure than a real results producing mod. Not meant to offend anyone, just my two cents.


----------



## BootAnimator (Jun 10, 2011)

TEK112 said:


> My thoughts are that no amount of undervolting will ever come close to offsetting the screen and LTE. We are talking 1-2 percentage points an hour with regular underclocking. For stability I don't try to push it. I like not having SODs and the occasional 5 second wait to wake the device or the inherent race to idle issues. If that means losing 10% over the course of a normal charge I am OK with that. The devs do a tremendous job UV from the stock values, going lower seems more like a self fulfilling adventure than a real results producing mod. Not meant to offend anyone, just my two cents.


My exact thoughts!

Sent from my Galaxy Nexus using Tapatalk 2


----------



## ashclepdia (Oct 10, 2011)

I saw someone mention under volt the screen..
I've seen a few mention that
But have not been able to find info on a method to try it.
Anyone point me in the right direction please?, thanks 

signature: 404 error


----------



## throwbot (Jan 2, 2012)

dpaine88 said:


> My thoughts are that no amount of undervolting will ever come close to offsetting the screen and LTE. We are talking 1-2 percentage points an hour with regular underclocking. For stability I don't try to push it. I like not having SODs and the occasional 5 second wait to wake the device or the inherent race to idle issues. If that means losing 10% over the course of a normal charge I am OK with that. The devs do a tremendous job UV from the stock values, going lower seems more like a self fulfilling adventure than a real results producing mod. Not meant to offend anyone, just my two cents.


Exactly-- and I'm def gonna trust what IMO says. I mean maybe it helps some people, but I get way better battery now than I did back when I was messing with undervolting a few months ago. If there is a way to under volt the screen other than dimming it, then I would love to hear it.

Sent from my Galaxy Nexus


----------



## tiny4579 (Oct 21, 2011)

ashclepdia said:


> I saw someone mention under volt the screen..
> I've seen a few mention that
> But have not been able to find info on a method to try it.
> Anyone point me in the right direction please?, thanks
> ...


Pretty sure that was a joke comment. Nobody has undervolted the screen. AMOLED screens are high power drainers, especially at higher brightnesses and the less black, the more drain. In fact I think white has the highest drain on AMOLED which is the exact opposite of LCD.

And as far as user undervolting, I don't do it on this phone as smartreflex undervolts automatically to a still stable level so I leave it stock. Most phones don't have this so user undervolting makes sense there. If you really want to undervolt then use a kernel with SR class 1.5 and undervolt below what SR class 1.5 has calibrated for you (there is a chance of weird issues though if you go below auto calibrated voltages).

And I do think that undervolting will save more battery than underclocking though underclocking will drop to a lower voltage with a max speed penalty. Also, as screen power draws most of the drain, followed by LTE or 3g data I don't see the need to user undervolt.


----------



## sonicxml (Oct 1, 2011)

ashclepdia said:


> I saw someone mention under volt the screen..
> I've seen a few mention that
> But have not been able to find info on a method to try it.
> Anyone point me in the right direction please?, thanks
> ...


You can under volt components of the screen, but this is only in the kernel source right now, not a sysfs value.

However, if the screen is undervolted too much, there will be problems with color reproduction (it will have a pinkish tint I think - I haven't tried undervolting it that much), so we can't under volt it too much.

Sent from my Galaxy Nexus using RootzWiki


----------



## sublimaze (Nov 17, 2011)

TEK112 said:


> My thoughts are that no amount of undervolting will ever come close to offsetting the screen and LTE. We are talking 1-2 percentage points an hour with regular underclocking. For stability I don't try to push it. I like not having SODs and the occasional 5 second wait to wake the device or the inherent race to idle issues.


I couldn't agree more. The two major battery hogs are the screen & LTE. Minimize those two variables, and you will maximize battery life. I have found that underclocking extends battery life a smidge, but undervolting does little more than invite sod's & overheating.

Sent from my Galaxy Nexus using Tapatalk 2


----------



## throwbot (Jan 2, 2012)

Kind of beating a dead horse, but I couldn't help but post this picture (heh). These are stock voltages on imos 3.2.2 exp 180 MHz:








Whooo-hoooo! Hoo hoo hoo. I just left EVERYTHING off but wifi, lte toggled off (3g area only) literally left the screen as dim as possible the whole time.

Sent from my Galaxy Nexus


----------



## ashclepdia (Oct 10, 2011)

Something I've found that seems to help with Battery concerning the screen (mostly during the night hours) is an app called screen filter
It allows you to dim the screen even more than stock settings, haven't been able to confirm if it's actually helping battery life or if I'm just imagining it, but I do believe it is, since the screen can be made so much more dimmer using that app it appears to draw less juice. Just thought I'd mention this in case anyone else wanted to check it out, great for night time use

Sent from my Galaxy Nexus using Tapatalk 2Oh and that screen shot above me, wow lmao, I'd never be able to reach that,.I like 4g too much lol, Oh, and I'm but the type to fret over battery life at all, of course i will try all kinds of things to see what I can squeeze out, but it didn't bother me at all to have to throw on the charger whenever I can,One thing I wish we had available tho is the mophie juice pack charging case that the iPhone has, that is the ONLY thing I'm jealous of when it comes to iPhone. I wouldn't mind needing to take the case off to hook to a computer if I had to, why don't they make one for us? It would be seriously awesome to have


----------



## ERIFNOMI (Jun 30, 2011)

ashclepdia said:


> One thing I wish we had available tho is the mophie juice pack charging case that the iPhone has, that is the ONLY thing I'm jealous of when it comes to iPhone. I wouldn't mind needing to take the case off to hook to a computer if I had to, why don't they make one for us? It would be seriously awesome to have


Maybe you'd be interested in a powerbag?


----------



## ThehulKK (Aug 31, 2011)

Why don't the extreme undervolters share their extreme settings? undervolting helps even if it's as little as 1%. That counts during the day.

Sent from my Galaxy Nexus using RootzWiki


----------



## zathus (Jan 2, 2012)

TEK112 said:


> My thoughts are that no amount of undervolting will ever come close to offsetting the screen and LTE. We are talking 1-2 percentage points an hour with regular underclocking. For stability I don't try to push it. I like not having SODs and the occasional 5 second wait to wake the device or the inherent race to idle issues. If that means losing 10% over the course of a normal charge I am OK with that. The devs do a tremendous job UV from the stock values, going lower seems more like a self fulfilling adventure than a real results producing mod. Not meant to offend anyone, just my two cents.


yup! I assume they are smarter then I am. I also assume that they want good bat life too. So whatever the default voltages are is were I leave them.

Sent from my Galaxy Nexus using RootzWiki


----------



## Gil Smash (Jul 22, 2011)

New franco has SR3.0, I'm gonna test it out tomorrow and see how she handles


----------



## ashclepdia (Oct 10, 2011)

ERIFNOMI said:


> Maybe you'd be interested in a powerbag?


Oh sweet
Check that out, never knew about those lol thanks!
Just watched a YouTube video review on one. Would be perfect for me, I am a line cook so I usually bring a change of clothes with me on the bus to work, would be perfect to be able to charge with my back pack.
Sometimes if I know I'll be out all day I'll bring my small laptop to plug into lol, thanks again!

Sent from my Galaxy Nexus using Tapatalk 2


----------



## ERIFNOMI (Jun 30, 2011)

ashclepdia said:


> Oh sweet
> Check that out, never knew about those lol thanks!
> Just watched a YouTube video review on one. Would be perfect for me, I am a line cook so I usually bring a change of clothes with me on the bus to work, would be perfect to be able to charge with my back pack.
> Sometimes if I know I'll be out all day I'll bring my small laptop to plug into lol, thanks again!
> ...


No problem. I kinda want one myself but I don't need one.


----------



## pedxing (Jan 15, 2012)

I think uv'ing has a benefit but I've never been too scientific about it. This was posted recently on Franco's thread:









And my uv settings.









This is with WiFi on all day, lte on but not used, auto brightness, 90 percent of the Screen on was reading ebooks using moon plus reader. The rest was some light web browsing. Screen off profile set to 350 mhz max. Most apps use a black theme, as does my home screen. Bluetooth on as well but not used.

Franco milestone 2
Codename android 1.2

350 to 1200 cpu, on demand governor.

Sent from my Galaxy Nexus using Tapatalk 2


----------



## pedxing (Jan 15, 2012)

Oh, 2100 mah battery, not stock but also not the massive seido.

Sent from my Galaxy Nexus using Tapatalk 2


----------

