Hardware requirements



there is a website built on wordpress, it gets ~5k visitors (~25k pageviews) per day, they make ~500 comments per day.

I was woundering if I move it to Xenforo, with 'Resource manager' installed, and an add-on for additional companies reviews/ratings page. What server hardware should I count on to have a room for 2x-3x traffic increase (~15k/day)?

My plan is to use nginx + php-fpm + mariadb software. I presume Xenforo gonna be the only software on the server. The question is: how much CPU and RAM do I need for my purpose (to run it comfortably, not on the edge of resources), based on your experience.

Also, are there any 'optimize server for xenforo' tutorials, with best caching practices and ither stuff approved by god-like xenforo admins? I mean, probably some (semi-)official here, on xenforo.com.

Thanks in advance.