[Samsung Galaxy Nexus] Tyrany:
Anarkia sorry for the big post =P this guide was made by Klathmon so a big thanks to him, i haven't made any changes to it but looks like a big startup to everybody

Undervolting, The Right Way

It seems alot of people dont know the proper way to undervolt their phones, so I'm gonna try to help out! This is my first attempt at a guide, and i tend to ramble so just tell me if it makes no ****-for-sense

Undervolting is great, it allows us to change the voltage in our phones while we use it! this can really increase battery life and reduce heat in the phone. but if its not done right, it causes many more problems than it fixes.

When you are following this guide you WILL have issues! This is not a generic disclaimer, it is the TRUTH! the goal here is to find out where your phone stops working, and you cant do that without causing it to STOP WORKING.

once again:

THIS WILL MAKE YOUR PHONE FREEZE, IT WILL HAVE AWFUL BATTERY LIFE, AND IT WILL MAKE BAD THINGS HAPPEN

But after its all done it should work much better

To start off, too much or too little voltage in the phone causes any number of things including:

Reboots (Screen Off and Screen On)

Lagging

Phone Overheating (Hot to the touch)

Reduced Battery Life (this includes the phone using more power, as well as reducing the battery's ability to hold a charge)

'Strange' issues with things shutting off/not working (WIFI, Bluetooth, your favorite app, ect...)

Many other 'weird' things

If you are having any of the above issues, and you are using a custom kernel, they may be caused by inproper undervolting.

THIS CAN BE THE CASE EVEN IF YOU HAVE NOT DONE ANY UNDERVOLTING YOURSELF!!!

Most custom kernels have undervolting build into them, and even 'stock voltage' versions allow overclocking, and those frequencies have no 'safe' voltage associated with them.

How to Properly Undervolt your Phone:

*this assumes you have no idea where to start, if you have some past experience, USE IT!!!*

First, Undervolting a phone the right way is not a quick job, like most things in life the more time you put into it the better your end result will be. For me i like to take an ENTIRE WEEK OR MORE to get all my settings down right. whenever you decide to do this, expect any and all of the issues i listed above to happen while you are trying to find the right settings.

Step 1: Starting Fresh

Disable all overclocking, undervolting, AND PROFILES on the ROM, you need to get the stock speeds working before you try to push the phone to its limit.

This will be your baseline. Use the phone like you normally do, text, call, surf the web, even let it sit in your pocket for a while. Do this for as long as you need to to be sure that everything is stable.

If you have any issues during this stage. STOP! add +25mv to every frequency across the board and start over. Do this up to 3 times if necessary, if after you have added +75mv to your stock voltage and you are still having issues, it is most likely something else in the rom causing the issue (rogue app, wrong kernel version, phone was dropped in the toilet too many times...) try to fix that first, or just try to ignore the issue, its up to you.

Otherwise, if everything is stable, Continue to step 2!

Step 2: Start Lowering Voltages

Lower all of the voltages by -25mv across the board. (If your phone needed any voltage added over stock to be stable, skip this step.)

This is where you begin testing the waters. Once again use the phone like normal, including some screen off time, as well as some CPU intensive tasks (playing music while websurfing, gaming, ect.)

If your phone is still stable after a good amount of time, then do it again. Your looking for the moment when things start to go wrong.

When you notice your first random reboot, or you start to feel the phone getting hot, or not responding STOP! you found the limit of your phone. Go back to the last working voltages you have and use them for step 3.

The more time you spend at this step the better your overall result will be! if you dont get any symptoms in an hour, they might show up later in the day, or overnight. Just take your time and have some patience.

Step 3: Lowering Voltages Independently

Now that you have a stable working phone. you can start lowering voltages one by one!

Starting with the lowest frequency, lower the voltage by -25mv.

Run this for a while, until you feel it is stable. Then move to the next highest voltage and do the same.

*If you have any issues, undo ONLY that frequency!!! Write down that frequency somewhere. you are done with it! you know that frequency is stable, and you shouldn't need to touch it again!!!

Keep doing this till you get to your stock maximum frequency, then continue to step 4!

*NOTE:* if any 2 voltages have more than a 100mv difference (125mv difference on Morfic's Kernels) between them, you need to raise the others around it to be equal or less than that. For exampe:

if at 1ghz, the phone is at 1000mv and at 1.2ghz the phone is at 1150mv. the higher one needs to be lowered (set 1.2ghz to 1125mv). if that is not stable for you then you must raise the lower one higher (set 1ghz to 1025mv).

Step 4: OVERCLOCKING!

At this point you should have a completely stable phone with no overclocking, grats! Now you get to start raising the frequency.

starting with the next highest frequency, set it to its stock voltage. if this is more than 100mv (125mv for Morfic's kernels) more than the previous frequency, set it to 100mv (125 for morfic) more than that.

run this until it is stable, and keep reducing it as much as you feel until you find instability. set it one step higher and move on to the next highest frequency.

if, after setting the voltage to 100mv (or 125mv) more than the last one, it is not stable, you need to raise the lower frequency's voltage up. sometimes this can cause a chain reaction that makes you raise 3, 4, or even all of the other frequencies up, if this happens you need to decide if that frequency is worth it to raise all the other frequencies to the next level.

If all is running good, proceed to step 5!

Step 5: The part where you hate me

(this step is optional, its just something i do to help with stability)

Now that you have a fully overclocked phone that is running as low of a frequency as it can safely, raise all of the voltages up by +25mv!

yes yes, i know, it sounds retarted to just undo that hard work and all that time you just put into finding the perfect voltages, but just hear me out.

Even if you spent a week on each step, did everything perfectly and tested everything you ever do on your phone and it is all completely stable. one day you are going to do something that will push the phone, which is running at its limit. so by adding 25mv to everything you are giving yourself some insurance. you may loose some battery life (i honestly don't ever notice a change with only 25mv) but when your phone alarm goes off in the morning to get you up for class, or you get that call you got that job you wanted, just be happy its not frozen on the table, or black screened in your pocket.

There you go! you should now have a stable phone with great battery life, and now you can stop bugging the devs about 'that strange reboot that is still there' or 'how every time you use his kernel you get black screens'

To Long; Didn't read Version:

If your having issues with your phone and you think its related to UV, and your much too busy/lazy/cool to read the above, try this: (Results will most likely be worse...)

Set (all of) your lowest voltages to 775mv (or 750 if you think your phone can do it)

Set your 1ghz voltage around 1000mv (give or take 50-100mv)

Set the highest speed to no more than 100mv below its stock seting.

Set the rest of all the speeds below 1ghz on a line between it and the lowest, and after 1ghz on a line between it and the highest. ex(From Morfic's T15 Kernel):