OPcache

Hi @callaloo, when the site not under caching (new post, purged or updated), refreshing the cache (crawler) and on admin panel, OPCache can still improve the speed and reduce the server load.

So if your site is not under development, turn on OPCache can is a good choice.

Thanks. Does it require anything else (like configuration) other than enabling the extension?

Yes, OPCache needs to be enabled on server-side, please check this article for more details.

Okay, thanks.