Apache (ab): mod_fcgid 4x slower than mod_cgi

modules for: regular cgi + fast cgi

LoadModule cgi_module modules/mod_cgi.so
LoadModule fcgid_module modules/mod_fcgid.so

test folder for regular and fast cgi.

DocumentRoot "/test"

<Directory "/test/rc">
    Require all granted
    Options +ExecCGI
    SetHandler cgi-script
</Directory>


<Directory "/test/fc">
    Require all granted
    Options +ExecCGI
    SetHandler fcgid-script
</Directory>

C test scripts : regular cgi + fast cgi ( named: 1.c )

Regular cgi:

#include <stdio.h>

int main(void) {
  printf("Content-Type: text/plain;\n\n");
  printf("ttt\n\n");
  return 0;
}

fcgi ( Fast Cgi )

#include <stdio.h>
#include <fcgi_stdio.h>

int main(void) {
while (FCGI_Accept() >= 0) { 
  printf("Content-Type: text/plain;\n\n");
  printf("ttt\n\n");
  return 0;
}
}

Benchmark with regular cgi: ( 3.61 seconds )

 ab -n 10 -c 10 http://<ip>/rc/1
 Time taken for tests:   3.613 seconds

Benchmark with fast cgi : ( 13.23 seconds )

 ab -n 10 -c 10 http://<ip>/fc/1
 Time taken for tests:   13.233 seconds

You're supposed to call FCGI_Finish() instead of return 0;, otherwise your program just serves only one request before exiting.