[EVO 4G Android Development] Product F(RED):
I hope this helps answer some questions guys. I don't know everything, but here are some things I do know:

Why should I wipe everything when flashing over a new version?

There are tons of bug fixes and new features being added (and removed) from each version of the ROM that will probably conflict with what's already on your device. That's partly why so many people have been having problems from the get-go. You have to wipe everything when upgrading (or downgrading): Factory Reset, Cache, and Dalvik-Cache. Some people swear they've had no problems just installing a new release over an old one, but sooner or later they run into problems. Don't make that mistake; do it right the first time.

I applied a mod and something went wrong. Do I have to wipe everything and reflash?

Unless you were on a different kernel then the one that came with the ROM, you can just reflash the ROM without wiping anything. If you were on a different kernel, then wipe your cache and dalvik-cache and reflash the ROM. After that, wipe both caches again flash whatever kernel you want.

What kernel will give me the best battery life and performance?

No two Evos, or any Android phones for that matter, are built the same. Seriously. Some people will say "X" kernel gives amazing battery life, while others will say "X kernel is horrible! Try Y kernel!". You really have to try them for yourself, giving your phone at least two days to readjust to the new kernel. You will probably see bad battery life/performance in the beginning, only to have it completely rebound later on, or vice versa. Unless a kernel is giving you absolutely horrible performance or battery life in the beginning, give it a chance.

The most popular kernels for Sense ROMs are:

- Netarchy-Toastmod

- King's Kernels

- Ziggy's Kernel (RLS4 has a special kernel written specifically for it)

Some things to keep in mind:

HAVS

- Hybrid Adaptive Voltage Scaling. This changes the voltage to the CPU depending on a number of things, but mainly it's based on what the phone needs when you're using it. Each CPU frequency is able to take more or less voltage than it needs, rather than a specific voltage for each frequency. You shouldn't use SetCPU profiles when using a kernel with HAVS as they will conflict and the benefits will be diminished.

BFS/CFS

- Two different types of schedulers of the kernel. Most kernels you encounter will come in two "main" flavors (I'll explain why later). BFS stands for Brain **** Scheduler. CFS stands for Completely Fair Scheduler. BFS tends to give greater, but inconsistent performance (not in a bad way though), while CFS tends to give lower latency but less performance. One is not better than the other; it depends on how you use your phone and what ROM you're using. Sometimes BFS will give you both battery life and performance, other times CFS will. BFS is intended for gaming mainly and things that hog the CPU. CFS is intended more for everyday usage (web browsing, texting, music) and focuses more on the system as a whole, as well as being more stable.

Undervolting

- A sub-category of HAVS, the goal of both it is to get the phone to draw as little power as necessary to run, while being both stable and fully functional. Usually, a kernel will come in just 2 flavors: BFS and CFS. But kernels that offer HAVS will come in 6: Aggressive undervolting, Less Aggressive undervolting, and NO-HAVS (3 for BFS and 3 for CFS). Aggressive undervolting tries as much as possible to keep electrical draw to a minimum. Less aggressive undervolting is for phones that start to act up because they're not getting enough power. And NO-HAVS is self-explanatory. Often times, you can get the same result using a NO-HAVS kernel with SetCPU profiles to lower the CPU frequency as battery life goes down.

Collin_ph Battery Tweak

- a service that's installed by flashing a zip in recovery. It tries to optimize CPU speed in relation to battery life. That is, it will lower your CPU frequency as your battery life goes down. It contains a few other tweaks, but mainly that's what it's for. It'll start working as soon as you flash it, but you can tweak it to your liking by going into your Terminal application and typing "batt-cfg". You can disable the tweak through the built in configurator, or completely remove it by typing "batt-rm" and following the prompts.

DO NOT USE WITH A HAVS KERNEL OR SETCPU PROFILES.

Why does my battery get drained [even] after I turn off 4G?

Sometimes the 4G receiver service gets stuck even after you toggle 4G off. The best (and only) way to fix this issue is to reboot the phone. It's a known issue and myn's head is probably going to 'splode from reading about it so much.

My battery life is STILL horrible. What else can I do?

You can try recalibrating your battery. How does it work? Your phone keeps track of your battery's discharge patterns and how often you charge it as well. By recalibrating your battery and then making your phone forget these stats, you can achieve drastically higher battery life:

1) Plug in your phone and let it charge until the LED goes green.

2) Unplug it, then when the LED goes off, repeat step 1 8-10 times.

3) Go into Recovery

4) Go to wipe -> wipe battery stats

You should have much battery life. Above all things, this requires patience.

Some other things to do are to get rid of task managers. Killing a task will only cause it to restart, thereby sucking up more battery in the process. Android is built on Linux and Linux handles processes differently than Windows. Applications that aren't being used don't eat up CPU cycles or memory. If really need to end a task, Force Close it through Settings. Some alternatives are:

Watchdog Lite

- This app will monitor running processes and lets you know when any of them are above the threshold you set (by default, it's 40% CPU). From there, you can choose to Whitelist, Ignore, or Kill them. In this case killing them is ok because usually they're system processes that need to be running, and killing them will restart them.

BatteryHistory

or

System Panel

- Both are applications to let you know what's using your resources. System Panel is more for analyzing real-time data while BatteryHistory is useful for seeing what's keeping your phone awake (aka a wakelock), what's eating your battery, and a quick glance at other things. NOTE: If you have Spare Parts, BatteryHistory is already built into it.

How come my camera doesn't work after flashing a new kernel?

This fix works for virtually all ROMs. Go to Settings -> Applications -> Camera -> Clear Data. It should work now.

Amon-Ra or Clockwork Recovery?

I'm not going to lie and tell you they're the same. Almost everyone now will tell you to use Amon-Ra because it has the ability to backup your WiMax image (which is very important since it contains your unique RSA key for access to the 4G network) and because it properly wipes the Dalvik-Cache. There are no advantages to using Clockwork other then it lets you browse for zips in folders. Basically: Amon-Ra