I just freshly installed Centos 8 and Odoo 13 with Postgresql 3.6. No Nginx installed yet. No sample data. No any other application on the server. Also i didn't install any odoo application.
To install odoo i folowed this step by step tutorial
https://thestack.net/2020/03/How-to-install-ODOO-in-CentOS-8-RHEL-8.html
Server has 8 GB RAM and 2 CPU