How to Change Screen Density (DPI) on Android [ROOT]
With the screen size increasing on phones every new release, its important to make use of the scarce resource efficiently. While most manufacturers stick to the standard DPI of 240 on the big screened phones (aka Samsung Galaxy S/S II, HTC Desire/Desire HD and the others, its too big to really make use of your Android efficiently. However, you still have hope. Remember, you need to be rooted to do this.
There are two ways of achieving this. One is from the phone. You need to have Root Explorer, or a similar app that can navigate to the root owned partitions of your phone. For a free app, ES File Explorer works too.
Method I - Do it from the phone on a Rooted ROM
1. Open Root Explorer.
2. Go to /system
3. Click on Mount RW (It should appear as Mount RO, that's when it is correct!)
4. Look for build.prop. Long press on the file and press Open file in Editor
5. Scroll down to ro.sf.lcd_density=240
6. Change the value to anywhere between 180 and 240. The lower the value, the higher density your screen will have.
7. Click on the Menu button, and Save and Exit.
Method II - Before flashing a Custom ROM (Including AOSP ROMs for your phone)
1. Open the zip file containing the custom ROM.
2. Navigate to System Folder, then extract build.prop to your Desktop.
3. Edit the file using Notepad or EditPad or Notepad++
4. Click Ctrl + F(Search) and enter 'ro.sf.lcd_density' or navigate to this line.
5. Change the value to your desired (Higher Value = Bigger font and lower density, Lower Value = Higher Density and smaller font)
6. Save the build.prop file and replace back into the zip file in the same place.
7. Flash the Custom ROM as per directions.
You should now have a phone with the same screen size but alot more density, slightly smaller text and more space to use applications on.
This guide can be used on all Android phone, even the smaller MDPI and LDPI phones to make your screen to appear bigger and more useful. However, you will have to tinker with the value unless you find one that suits you best.
If some applications cannot span properly to the new screen size, download Spare Parts from the market, uncheck Compatibility Mode in the options, and reboot. Some launchers may act wierd, however most do look good with a higher density look!