What can be done to improve the performance of Magento?

Question

PHP

There is an unloaded Magento 1.9.2 project with attendance up to 100 people per day. But the speed of work leaves much to be desired even at zero load. I have already exhausted most of the standard optimization methods:
1) Traffic compression + expires headers via .htaccess
2) Image compression with utilities
3) Magento Community native cache
4) Full-page cache with a separate module
5) Optimization of MySQL parameters
6) Session caching in Redis
7) Disabled all unnecessary modules and functions (which are disabled via app/etc/modules/)
8) The template was bought ready-made, but I wouldn’t call it “bydlokodsky”
9) I also tried minifying and gluing CSS/JS, but then some of the modules “break”, in anyway, it didn't make things any better.
10) Couldn't get it to work with PHP7

What's on the server:
Centos 6 via KVM, 2GB RAM, PHP 5.6 mod_apache with OpCode

With an unheated FPC cache, page loading speed is around 5-8 seconds. With warmed up - it feels like 2-4, but third-party tools like webpagetest show up to 10 seconds anyway.

Answer 1

Is the log of long queries to the database enabled? If not, turn it on and see.

Answer 2

Explore.
Perhaps these are large SQLs that are incorrectly composed.
Maybe the channel is bad.
Maybe the server config is wrong.
You need to find the cause and fix it.

Answer 3

Url to studio