opcache for php5.6 was faster than xcache's opcache
xcache is not compatible with php7
xcache has not had any commits to its github project since January 14th, 2013
apcu is a drop in replacement for xcache's datastore
Based on these facts, the only logical option would be to use php7's internal...
Often when you enable an opcache, memory usage of individual php processes goes down substantially because they don't have to include actual interpretation of code in the memory, and then the bytecode is a pooled memory space
That wouldn't explain THIS big of a drop though
Redis really, really, really, really does not need a gui
It's so incredibly simple in nature that its configured by a text file, and managed through baby's-my-first-database cli
It's nothing like mysql or anything for complexity
It doesn't matter if you have 100 posts, if those 100 posts get 10 million views a day, and you aren't using a static file caching system
Redis is just awesome, and is super simple to setup
If your site is lightly loaded, you likely won't see much of a difference in load
7% vs 10% is inconsequential
What you will see however, is a reduction in time to first byte on the html document
Those are entirely different types of delays
memcached reduces DB calls (redis does it better)
php 7 is faster at php
Having a data store will reduce db calls, while also reducing php time can appear to cause no performance change because you had the performance improve, and get worse...
"Plesk 12.5.x offers FastCGI w/Apache, PHP-FPM w/Apache, and PHP-FPM with nginx."
FastCGI isn't a PHP processor, it's a protocol to transmit requests. That's like saying that you generated a html page using HTTP. It doesn't make sense.
FastCGI can't process PHP code. It's not a PHP processor...