Apache + mod_php performance

I am not impressed by Apache + mod_php performance on VMS.
The basic numbers I see (simple PHP code for getting some data
out of a MySQL database and displaying) are:
Apache + CGI : 4 req/sec = 240 req/min
Apache + mod_php : 11 req/sec = 660 req/min
Tomcat + Quercus : 127 req/sec = 7620 req/min
(VMS x86-64 9.2-2, Apache 2.4-58, Berryman PHP 8.1,
Java 8u372, Tomcat 8.5-89, Quercus 4.0)
That CGI is slow is no surprise. Using CGI for performance
is like doing 100 meter crawl dressed in medieval armor.
But I had expected much better numbers for mod_php. Instead
of the actual x2.5 and x10 I had expected like x10 and x2.5
between the three.
Anyone having any ideas for why it is like this and what
can be done about it?
Arne
PS: And before anyone jump at the great Quercus numbers - yes
     Quercus is a very nice product, but Resin stopped development
     many years ago and it is stuck at PHP 5.x - so it is only
     a solution for DIY PHP 5.x code not a solution for any
     recent version of common MVC frameworks like Lareval.