ive got a site that uses ajax chat about to launch. we've got a pretty good dedicated server. my question is this:

how many people using this site, chatting at a time (via ajax) would you estimate before the server just got bogged down? I'm trying to figure out how much time we have to move the system over to a more scalable push technology.

1,000 users? 10,000? 100,000?

Any insight is appreciated. Thanks

Anyone know at all??

There's nothing particular to AJAX that is scalable or not scalable. It is just going to depend on how how many requests are made to the page, and how much information is returned from it. There is not really an answer to your question, it just depends.

AJAX works with a normal HTTP request. As far as the server is concerned this is no different than requesting any page, albeit probably a small one in this case. You are better off calculating how much data is returned by each AJAX call, then asking a server administrator exactly how much load a single computer can take, per minute, per 30 seconds, whatever.