serve_site() only updates the revised Rmd post (typically a single post): https://bookdown.org/yihui/blogdown/local-preview.html but it calls Hugo to rebuild the whole site, which should be lightning fast (typically 1000 pages in 1 second, unless you have hundreds of thousands of pages or are on Windows...). If Hugo is slow anyway for some reason, you may try a different LiveReload approach: https://bookdown.org/yihui/blogdown/livereload.html, which is what I use by myself.
1 Like