Ajax response time higher than with CI3

Hello,

Recently i've worked on rewriting my web app with a lot of ajax calls to CI4. I noticed that response times are higher than when i used a CI3. Differences were not so much annoying but they were puzzling. With CI3 on my web app ajax call response times were around 70-90ms while with CI4 they were around 120-140ms. I thought that maybe there were a problem with something other like a queries to database or sth... (but it would be confusing because i rewrote 1:1 previous web app). So i made a test controller with a test view with ajax call.

Simple controller:

PHP Code:

public function test1() {
 $array = array();
 $object = new stdClass();
 $object -> time = time();
 array_push( $array, $object );

 echo json_encode( $array );
 } 


And a simple ajax call:

Code:

$( document ).ready( function() {
$( '#test' ).bind( 'submit', function( e ) {
e.preventDefault();

var data = {};

$.ajax( {
type: 'POST',
url: '<?php echo base_url( 'Test/test1' ); ?>',
success: function( response ) {
console.log( response );

$.each( response, function( i ) {
$( '#test_table' ).prepend( $( '<tr>' )
.append( $( '<td>' )
.append( response[i].time )
)
);
} );
},
error: function( xhr, ajaxOptions, thrownError ) {
console.log( thrownError );
}
} );
} );
} );

And i made tests. CI3 ajax call response times: 30-50ms while CI4: 60-80ms. CI4 environment were ofcourse set to production. On environment set to development they were even higher... Is there any explanation why is that?