I don't know. The old server started getting reeeeaaaalllyyy ssssllllooooowwwww at 146. I think that people would just give up and leave because pages took too long to load. I did see it up to 230 once but it was slow like molasses.
The true test will be the next workday. This board peaks noon - 3pm on weekdays.
When you think about it, if 200 people are continuaously loading pages and searching and generating private messages, that is a lot of stuff for one computer to do.
This one should be able to handle a lot.