The server runs for about 10 people usually. I dedicate 1Gb of RAM to it. It doesn't seem to need much more. With this recent 1.4.2 patch, after about several hours of being on, the server would use 500mb of RAM on idle. When there is no one online. Usually it only uses about 60mb on idle. This only happens after leaving the server on for a few hours. It means I have to constantly restart it every few hours to reduce the RAM usage and ultimately the slight lag it causes.