[FIXED] Which web server software to use

Issue

I have VPS with 3 websites hosted.
Only one is a high traffic with around 3000 visits/day.

VPS Specs
CPU: 2,3GHz
RAM: 512MB
SSD: 20GB

I configure it to use 2GB swap with swappiness 3, so it will use it only when RAM is critical.
Swap is almost non-used because everything consumes about 280-350MB RAM on medium load.

Currently I use LAMP -

Linux Debian 7 Wheezy AMD64
Apache2
MySQL
PHP

Other are Postfix, Webmin, dove-cot, APF Firewall, DDoS Deflate.
It is run via a Cloudflare network for best performance.

Now, I heard good things about ngnix and Light-httpd.
Which one I should choose, or to stay with Apache?
Performance are not very good with a much users online, If I see good, fu*king Apache uses separated sub-process for every visitors online?
That's ridiculous.

So please, recommend be the best one to use on current server? Thank you in advance!
Please note that I use a lot subdomains, so I need that function.

Solution

check the following white paper http://www.whisperdale.net/11-nginx-vs-cherokee-vs-apache-vs-lighttpd.html

Answered By - Saddam Abu Ghaida