Its possible to change
idea.properties files without editing them in the PhpStorm installation folder.
Follow the steps below:
Edit Custom VM Options...
Confirm the creation of the configuration file, if prompted
Add following lines if you want to use OpenGL
# This line could already be there depending on your PHPStorm version -Dawt.useSystemAAFontSettings=lcd -Dawt.java2d.opengl=true
Add the following lines if you want to increase memory allocated to PhpStorm (improves performance in large projects)
# This line could already be there depending on your PHPStorm version -Xmx750m
Save the file and restart program.