Varnish leaves it to the OS to decide what pages to keep in RAM and which to leave on disk; essentially to avoid the double-buffering problem and because the OS has a larger view of the total machine's requirements.
But with wp-supercache I already have that approximate architecture. Files are on-disk, Nginx selects them, the OS notices that some files are frequently accessed and silently caches them in RAM. Everyone wins.
And I don't need to add ESI directives to my themes to get Varnish to handle frequently-updated material correctly.
Varnish leaves it to the OS to decide what pages to keep in RAM and which to leave on disk; essentially to avoid the double-buffering problem and because the OS has a larger view of the total machine's requirements.
But with wp-supercache I already have that approximate architecture. Files are on-disk, Nginx selects them, the OS notices that some files are frequently accessed and silently caches them in RAM. Everyone wins.
And I don't need to add ESI directives to my themes to get Varnish to handle frequently-updated material correctly.