The faster the website loads the better for it to be on the top on search engines pages.
But if you are enemy to such big beast as Google, they will bring your website down no matter how good SEO you did and no matter how fast is your website, the stupidity of Google is that it thinks that they will keep my websites at the bottom for more time but they not know that i hold the most important website names in the world and i will destroy this companies using them.