Simultaneous execution of php script/file

Question

i have a script that tried to simulate an http connection and send/receive some xml to a server to check if it's working fine . i call it simulator . now i wanna to do some benchmark on the server with this simulator and check how much Bandwidth used to transfer this xml data and how much resource consumed in every call .

in first place i tried a bash script to run my php file as cli . but it was huge ram usage when we run about 3000 process of this script .

i tried about pcntl_fork but i can't make it work because it's running scripts in serial mode and i don't have any concurrency in execution .

also tried to use pthread but i failed .

do you have any idea how i can run simultaneous execution of my script ?