Our repository offers the largest collection of NGINX and Varnish packages for smooth production use. The try_files NGINX directive simplifies setting up SEO-friendly URLs, eliminating the need for PHP involvement in serving static content. However, try_files comes with a performance penalty due to file existence checks, which can be magnified as traffic grows. In light of this, an alternative configuration without try_files can be more efficient and secure, directing most requests through PHP while having NGINX serve static files directly. By carefully structuring the configuration and specifying file types, unnecessary performance impacts of try_files can be avoided. The use of open_file_cache can also mitigate the performance impact of try_files to some extent.
https://www.getpagespeed.com/server-setup/nginx-try_files-is-evil-too