Which is faster one MySQL virtual server (4CPU, 4GB RAM) or 2 MySQL virtual machines (2CPU, 2GB RAM each)?

Question

MySQL

Hello, there are several sites that actively use Mysql. The sites are divided into two virtual servers (due to the fact that they need different software, and you can’t put it on one server), the load is approximately the same. So I'm thinking either to make a single MySql server for them or split it into two, which will be faster and better?

Answer 1

Better one, but proper database setup.
Two instances incur sync and network overhead.
Memcached or analogues are also advised. And if it's a website, it should be on the same machine, since access via a UNIX socket is much faster than via a network.
Please note that it is also better to connect memcached via UNIX socket.

Answer 2

the smaller the database and the fewer queries that occur in the database, the faster the query is executed.
But! Without knowing the architecture and size of your database and site code, and 1000 other little things, it is impossible to answer your question unambiguously.