More cores or higher clock speed

Good morning,

I am planning a project in the near future in which more than 200 active users will make calls on a Janus server via the SIP plugin. I would order a new server for the operation. In “Performance analysis of the Janus WebRTC gateway” Meetecho used a 16 Core CPU with 2GHz clock speed for the server.

Now I ask myself whether I should rather look for more cores or a higher clock speed when buying a new CPU?

I hope one of you can answer this question for me.

Kind regards
Simon Fröschl