Set the JVM Max ,Min heap and Perm size of JVM in AEM

Add the below details in start.bat/start.sh file of AEM:

CQ_JVM_OPTS='-server –Xms8192m –Xmx8192m -XX:MaxPermSize=1024M 

where as 

• Xms is Min heap - size can be increased depending on the your instance RAM size
• Xmx is Max heap - size can be increased depending on the your instance RAM size
•  MaxPermSize size can be increased depending on the your instance RAM size

finally restart the instance.

Enable Minify Option to Compress CSS and JS file before rendering

Use the belwo details:

Go to this URL: http://localhost:4502/system/console/configMgr

•  Search for: DAY CQ HTML LIBRARY MANAGER
•  Enable the Minify Option (check the checkbox)