One of the main features in my website is a simple One-to-One chat.
I'm debating whether or not I shall dedicate a server (or a cluster) for the sole purpose of this chat feature. The simpler option would be combining this feature as part of the web-servers and just scale out when necessary.
It is worth mentioning I'd like in the future to enable images transfer within the chat.
So what is the better option and why?
Well yes, Whether to use another dedicated server is not depending on how much traffic your site will have to handle. If you're dealing with images It will be a good idea to store them in another server and keep the root server clean.