question

>>Is it better to share one instance of the server for multiple games to save money? is there a much difference in terms of costs if I request new multiplayer server for each game compared to have only few instances of servers and request new one only if players count exceed server capacity?

For clarification, PlayFab Multiplayer Servers are billed based on the consumption of the VM cores rather than the number of server instances. It means for the virtual machines with the same cores, increasing the number of server instances per machine will not increase the cost of our service. Please refer to our documentation - Billing for PlayFab Multiplayer Servers 2.0 for more information about the price of our multiplayer service. You can also navigate to this page - Estimate your monthly charges for MPS (playfab.com) to estimate the MPS billing of your title.

And since our matchmaking feature only supports allocating the separate server instance for every match. If you want to allocate one server instance for multiple matches, you will need to implement the allocator server on your own.

For the above reasons, we would recommend you directly increase the number of servers hosted on each VM to reduce the resources consumed by each server.

>> if so how to compute maximum how many players can fit one instance of the server?

How many players a VM can hold depends on the specific game logic and the computing powers of the VM cores. We would suggest you conduct a stress test on your own to determine how many server instances can be hosted on a VM.