[XPERIA X10 General] xeviro:
Since Sony Xperia X10 is now running on 2.1, topics related to 1.6 is not mentioned here.

This thread are created based on compilation of other threads related to optimization, and meant as an entry point for user interested in optimization.

Understanding your Android

Just to put something short, so we can understand our Android and some points related to optimization better.

Android is an open source operating system owned by Google that is maintained by Android Open Source Project (AOSP). The operating system is based on modified Linux kernel, where most of the application is written in Java language and running on DalvikJVM.

Android do things differently than old generation OS like Symbian, and below is the explanation related to performance.

Unlike Symbian, Android designed to have as many as application loaded and running in the OS, it maintain list of least used application that will be unloaded when a requests for more memory is made when the free OS memory is already low.

These are the nature of JVM, where allocation and deallocation of memory is managed by garbage collector as doing things in bulk is faster then working with small chunks. So you don't have to be alarmed when you open a memory viewer application and see your Android is running on low memory. Freeing RAM with task killer is only momentarily, as you uses the phone again, the free memory will goes down again.

Android phones stores system application, data and files internally in NAND flash area and stores user data in internal memory storage or external storage such as SD cards. This memory is different than your operating sytem memory.

Operating system memory is memory allocated for the kernel, native application and most application you download from market. Installing a lot of application will not directly reduce free RAM, nor uninstalling or removing files will increase free RAM directly. Action such as removing ringtones, wallpaper and even Sony PC Companion ISO will not free your RAM

In general there are two type of android application. One is a standalone application that only run if you open the application, and the other one is running even you haven't open the application which called service.

By design, guideline and suggested practice, application should not continue to run lengthy processing when it get pushed to background via home button, back button or switching to other application; properly build application will just go idle. Which means you should be less paranoid about application eating you processing power.

But service is meant to run lengthy operation as they don't have user interface and runs in background. Some service meanth for pushing or pulling data from internet, reading your files and do processing like playing songs, or just doing something then update the widget just to make you happy. Unnecessary services are the things that you should be aiming if you want to optimize your Android.

General FAQ about Optimizing Sony Xperia X10 2.1

I just updated to 2.1 and my phone really feel slower than 1.6

Since you had been using 1.6 for quite some time, your SD card should have quite a lot of photo and media. Just after you updated to 2.1, and add your Google and maybe Facebook account, the new Face Recognition service is actually already starting to scans all your photo, then when your Google and Facebook contact arrived, it will try it best to match photo and contact. This new Face Recognition really kicks hard in your processor, then after a while your phone will be as fast and even better than old stock 1.6.

I still feel that the phone is slow, is there any simple and quick way to optimize

The simple and quick to optimize your phone instantly is by changing the 2.1 dalvikvm to JIT capable dalvikjvm. You can read and apply them by reading the thread referred below, but before you do that open the below link in background tab and please do read more first.

Android 2.1 OPTIMISER V002 by Jerpelea

2.1 Customizer v0.99.1 by ttxdragon

Both optimizer contains script that will erase your "junk/unused" application from your phone, be sure to read them first before executing. My suggestion is you apply JIT modification first, before going optimizing by remove your "junk/unused" application.

Please do remember that you have to Root your X10 first.

How to root the phone

You can root the phone using methods below.

OneClick z4root Android Application

SuperOneClick Windows Application

Is [INSERT APP NAME] here is save to remove?

By removing unused application, you will gain certain amount of performance gain. Below are the links with app list.

2.1 Customizer v0.99.1 by ttxdragon

Official List of Apps that Can be Removed from a 2.1 x10 by exekias

And still a lot more in other Sony Ericsson X10 forum section but those two is quite complete

And in case you forgot to make backup you can go to

2.1 System Apps - In Case You've Deleted Them by XperiaX10iUser

After doing all that my Quadrant Benchmark is still low

You should run Quadrant as least two or three time or until you get best score, the first one usually yield low score, because a lot of memory allocation process to Quadrant happening during the first run.