Re: BuddyPress and Shared Hosting
As you say:
I know this is all very hypothetical and hard to judge…
So, given that as a premise, this is just my opinion. It seems to me that your current setup should be fine for what you’ve described. The physical memory seems low for a dedicated server, but you more than likely have sufficient virtual memory allocated to help alleviate some of that inadequacy.
The server’s physical HD space is not an issue since I assume that you have unlimited storage space with your dedicated hosting account. After all, hard drive space should be cheap.
When WPMU sites get to 1000 active users or so (or fewer very active users), many people find that they need a dedicate VPS or even dedicate server to handle just that single site. But, as I’ve said above, it depends on too many variables to accurately provide a detailed set of guidelines. One site may have little issues with several thousand users whereas another has issues at 500 users.