Today i moved a high traffic WordPress web using from Apache + PHP 5 to Nginx + PHP 7.2.
Here is a graph provided by LiquidWeb (server provider).
With Apache, load was like 8.
After switching to Nginx + PHP-FPM, load come down to 2.
Here is sar result.
With Apache idle CPU was approx 72. With Nginx we have 90%+ idle CPU most of the time.
Here is NewRelic Web transactions graph. The break in data is due to PHP 7.2 have no newrelic module installed. So i just switched back to Apache for a while, reinstalled NewRelic for PHP 7.2, then turned Nginx back on.
NewRelic Apdex Score went from poor to fair.