I just tested httpd 2.4.25 against nginx 1.10.3 on my workstation using the default configurations and it seems things are much better on the memory consumption area (than a quite a few years ago when we made the switch to nginx)

* httpd 2.45.5, default config (prefork), peaked at 24 processes and ~8MB RSS each (192MB) => 88k req/sec

* nginx 1.10.3, default config, peaked at 8 processed and ~4MB RSS each (32MB) => 199k req/sec

I thought all the default modules could be slowing httpd down so I built the most stripped down version that would allow me to run it and also switched to mpm_event:

* httpd 2.45.5, stripped down mpm_event, peaked at 5 processed 8MB each (40MB) ==> 89k req/sec

Both mpm_prefork and mpm_event had similar numbers. Where should I be looking at if I want to increase the request rate?

EDIT: stripped down mpm_prefork got me 120k req/sec but I saw a few defunct processes which is scary.