PageSpeed: Improve server response time
Long web server response times delay page loading speeds. Page Speed expects your server to begin responding to resource requests quickly to ensure a quick page load time. For each resource request, your server needs to begin sending the first byte of the resource within 200ms of the request being sent.
Feel free to use our recommendations in our 'Why is my page slow?' guide. Our tips can help you get better server response times, through various methods.
Note: This rule is experimental.