Apache content structure

Is there a performance improvement by placing your web content on another hd? Because I will be running .NET Core apps in addition to regular html, some apps will be public, others will be members only.

mod_disk_cache and mod_mem_cache would probably be of more immediate value, particularly if some/most/all of your content is static data.

Varnish would be the big hammer solution…

With Varnish do I still add the mod_disk_cache and mod_mem_cache?