> The margin by what metric? My Apache processes are less than 500KB each.

Resource usage in high active connections situation. I remembered I got it that low back then, but isn't the number raise by each active connection? 1000*500KB is 500MB. Nginx stays at 3MB.

Sorry, I deleted the parent because I replied at the wrong tier, but at any rate. Yes, with pre-fork MPM each connection gets its own process [1]. You don't need a 1:1 ratio of process to concurrency though. That's just silly.

Yes, Nginx is more resource frugal (especially RAM), but you can serve a whole lot of visitors with Apache using 30-50 MB of RAM, which isn't prohibitive, depending upon your needs.

To re-state it: I am not claiming that Apache is a better web server than Nginx, and I do think that every Apache admin should look at and understand Nginx, because it's a different beast, and it just might fit your needs better. But I talk to a lot of really ill-informed people who look at the output of `top` and think that each Apache process is consuming something crazy like 17 MB of RAM a piece. This is generating the perception that default answer is to move away from Apache to something else entirely. That's a wrong-headed way of looking at the problem.

1 - The author's suggestion to turn off keep-alive is a good one in memory restricted environments, btw. This prevents long-running connections that tie up memory.