I couldn’t find the minimum hardware requirements for a CentOS 7 minimal installation on Baidu after searching for a while, so I visited the official website and found the information below:

CentOS requires at least the following amount of RAM:

Local media installation (USB, DVD): 768 MiB

NFS network installation: 768 MiB

HTTP, HTTPS, or FTP network installation: 1.5 GiB

Original source:
https://docs.centos.org/en-US/centos/install-guide/Steps-x86/#sect-installation-planning-disk-space-memory-x86