[TYPO3-english] need advice - recommended server specs

[Joko Nurjadi]

Hi,

I plan to develop about 20 websites with typo3, I need some advices related to infrastructure issues:

1. Server Hardware requirement.

I've just read this http://typo3.org/about/system-requirements/, but it doesn't mention about recommended hardware specs for server. What's recommended RAM/Processor?

2. Is it possible (or good idea) to put all websites (20 websites) in 1 server? 

Thanks for your help.

Joko