I haven’t heard any benchmarks as it’s up to you on setting it up (nginx/apache/phpcgi/phpfpm/etc….).
It’s even harder to compare pound for pound because of the extensibility bbpress affords you with wordpress and buddypress. Even the plug-ins that each trio of apps afford you.
There is a point when it’s not about how many users you can squeeze out of a single VPS, it’s about building a site… a community and what is the best software & hardware able to do that.
Of course, when your scaled to the limit with hardware, software, and users to that of say Twitter it’s a different story.
On their curve, no matter how much hardware they add, curbing simple things like response time become a huge battle. At this scale it’s in your best interest to develop something proprietary as such they have and are doing.
In your case though, your probably better off worrying about ‘how do i scale my forum installation’ , and ‘what forum software gives my users the most benefit’, than asking ‘how many people can i house on my vps/dedicated/box/PS3’.
Even having said this all of this, out of the box there is less overhead in the bbpress architecture than with PHPBBx.
Take all of what I said with a grain of salt, and a beer in hand.
We have 13000+ members so far on dual core and 2gb ram with lighty, working great
Vanesta, Can you give me link to this forum?
There are already sites running bbPress 0.9 with many more users than that.
Only thing I would suggest as I have in the past is that if it’s a commercial project with income, you should always be considering vbulletin which is no-nonsense, high end features/performance right out of the box. But it’s not cheap and everything worthwhile for it is usually pay-only also.
bbPress is for do-it-yourself-ers who want to make something that either blends into an existing design or you want something fresh that doesn’t look like every other cookie-cutter forum.
__CK_ what kind of hardware are you using?
My hardware wouldn’t matter because I’m running a small fraction of the number of users you are asking about. I am however running litespeed instead of apache which can double the performance of most servers.