How to give more memory to IntelliJ Idea 9-11

On Mac, $IDEA_HOME/Contents/Info.plist

 ~: grep --context=5 Xmx /Applications/Maia-IU-94.426.app/Contents/Info.plist 
            <string>true</string>
            <key>apple.awt.fullscreencapturealldisplays</key>
            <string>false</string>
        </dict>
        <key>VMOptions</key>
        <string>-Xms128m -Xmx912m -Dfile.encoding=UTF-8 -XX:MaxPermSize=250m -ea -agentlib:yjpagent=disablej2ee,disablecounts,disablealloc,sessionname=IntelliJIdea90 -Xbootclasspath/a:../lib/boot.jar</string>
        <key>WorkingDirectory</key>
        <string>$APP_PACKAGE/bin</string>
    </dict>
</dict>
</plist>

On Windows/Linux, %IDEA_HOME%\bin\idea.vmoptions