PHP server change between Apache and Nginx: 3x performance loss - php

Question

Our current infra works fine with Apache + PHP and MySQL managed elsewhere. I have not done any particular optimization on this server. These are the initial configurations. Except for memory_limit and execution_time.
I am in the process of changing our infra to something more modern with bigger server and Nginx + PHP-FPM.
While working on this problem, I realize that we have big performance losses using this new infra. It's a shame to have more powerful servers and it's slower.
I watched the server load and nothing. Memory and CPU are barely 2%
I pulled out my Inspector badge and began to eliminate guesswork. Obviously, my tests use exactly the same case, same framework, same version of our app, ...
Here are my tests:
I installed on newer Apache + PHP servers and in fact Apache is even slower than with Nginx (no surprise :)).
I created a simple "hello wok" PHP file to test if it could come from Nginx. So I am not using our framework which could be involved.
Everything is normal TTFB times are almost equivalent (~ 24ms). Nginx on the new infra is 2ms faster.
While going with our framework, I added a piece of basic code which amounts to doing a "Hello wok" but using our framework.
Ah there, we have a problem. Finally ! Old infra 61ms, New infra: 184ms.
The new infra is therefore 3x slower to load the framework.
Obviously, I did a lot of optimizing the existing code but seeing that, I'll never be able to optimize it and make it 3x faster.
In all cases: Why the same code takes 3x longer to run on different environments.
The only thing that occurs to me right now is a PHP and PHP-FPM configuration problem.
In these configurations, do you know of any reasons that could have such a slowdown?
Obviously I looked for and tested things to optimize but it's always the same.
Here is my php.ini file:
date.timezone = Europe/Paris
opcache.enable = 0
apc.enabled = 1
apc.enable_cli = 1
upload_max_filesize = 128M
post_max_size = 128M
realpath_cache_size=4096k
realpath_cache_ttl=7200
display_errors = Off
display_startup_errors = Off
access.log = /proc/self/fd/2
error_log = /proc/self/fd/2
error_reporting = E_ALL ^ E_STRICT
; output_buffering=4096
pm = dynamic
pm.max_children = 5
pm.start_servers = 3
pm.min_spare_servers = 2
pm.max_spare_servers = 4
pm.max_requests = 1000
max_execution_time=600
memory_limit = 2048M
opcache.enable = 1
opcache.enable_cli = 1
opcache.memory_consumption = 2048
; opcache.interned_strings_buffer = 32
; opcache.max_accelerated_files = 100000
; opcache.max_wasted_percentage = 15
opcache.revalidate_freq = 0
; opcache.validate_timestamps = 1
Do you have any advice ? recommendations ? ideas ?
thanks in advance
Are you doing well
EDIT #1
Server Information:
Old server:
VM with 1 processor / 2GB RAM
No database, just Apache + PHP
Framework specific cache system: file
$ cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 15
model : 6
model name : Common KVM processor
cpu MHz : 3504.002
cache size : 4096 KB
[...]
New server:
Docker container on a 3 processor / 4GB RAM server
I do not have the speeds of each processor. This is vCPU.
No database
Container PHP-FPM + Container Nginx
Framework specific cache system: APC
processor : 0
vendor_id : AuthenticAMD
cpu family : 23
model : 1
model name : AMD EPYC 7281 16-Core Processor
stepping : 2
cpu MHz : 2096.062
cache size : 512 KB
[...]
processor : 1
vendor_id : AuthenticAMD
cpu family : 23
model : 1
model name : AMD EPYC 7281 16-Core Processor
stepping : 2
cpu MHz : 2096.062
cache size : 512 KB
[...]
processor : 2
vendor_id : AuthenticAMD
cpu family : 23
model : 1
model name : AMD EPYC 7281 16-Core Processor
stepping : 2
cpu MHz : 2096.062
cache size : 512 KB
[...]
Others :
The database is managed in a provider
The sessions are stored in the database

Answer 1

Despite what you will read all over the internet, under low loads, Apache+mod_php is significantly faster than nginx+php-fpm. The latter architecture offers better capacity and scaling. That does not explain the difference in performance reported here.
The only thing you have told us about the two infrastructures is that one is old and one is new. If all you know about them is that you clicked a button in a cloud control panel then it can be difficult to find out more (if this is a Linux VM, check /proc/cpuinfo and mpstat paying particular attention to the steal time). The metrics you measured by testing will be highly dependent on single thread performance which is not a good indicator of throughput on a multi-cpu machine or any machine under heavy load.
But the first place I would be looking is at the storage latency / increasing opcache.revalidate_freq.