This is a theoretical question.
I find it difficult to estimate the server needs of a website and there are few examples for me to estimate on my own.
What i basically ask is this:
Let’s say i have a VPS with unlimited bandwidth, a 2 core cpu, 4gb ram, 10gb hdd. I install wordpress on it and post 1000 posts. Each post contains 1 image (100kb) and a few paragraphs of text. Considering that i have no themes, plugins etc, how many registered users will be able to view the blog unproblematically at the same time (view posts and post comments), how many with increased loading times and when will the blog become unusable from the amount of users. If i double my VPS specs will the number of accommodated users scale linearly?