Agner Fog's optimization guide is worth a very close reading: https://www.agner.org/optimize/microarchitecture.pdf

If you want smaller chunks, Denis Bakhvalov is starting to hit his stride with a nice series of blog posts: https://easyperf.net/notes/

If that's not enough, Ingve (who submitted this) has made literally thousands of submissions, and a surprising number are excellent articles on optimization: https://news.ycombinator.com/submitted?id=ingve