phpBB / shared hosting questions

I have a smallish phpBB forum (~50k posts, max concurrent users ever = 58, typical peak concurrent users = 10).

I run it through another service provider right now. The forum has become dreadfully slow as of late. I'm probably going to move the operation to Hostgator anyway, simply because that other place's tech support is not supporting my tech, but I had a couple questions first, in case anyone knows:

1) Is there anyway for me to know why the forum is so slow? I suspect the server itself is overloaded. I'm well under my disk usage and bandwidth but I suspect the CPU/RAM is pegged from whoever else I'm sharing that server with. Is there any way to figure out what's going on? I have shell access and other goodies. It's actually quite a nice service provider in terms of offerings, or it was, right up until my forum started slowing down.

2) Is there any reason to suspect that a phpBB of that size ought to run so terribly on a shared server?

3) Is there happy news like, "Hostgator watches CPU usage closely and a phpBB forum of that size should never be taking 5+ seconds to perform an operation"?


Similarly, I recently attached a wiki to my site and again some simple page loads end up taking 5+ seconds for a blank page with some text on it -- HTML is fast but anything that hits the database (like the forum and the wiki) vary wildly from "fast" to "wtf?"


Thoughts?

Oh, I guess a good related question would be this:


Any idea on what size a phpBB forum / mySQL database has to be before it's impractical to expect a shared hosting plan to support it?

(I imagine Hostgator must have had to tell some people to move to a bigger hosting package because they were using up too much CPU / RAM. If they were a phpBB forum, how big were they?)

[Serra]

If your site is on cPanel, you can look at the system to see if it is overloaded under "Service Status".

(I imagine Hostgator must have had to tell some people to move to a bigger hosting package because they were using up too much CPU / RAM. If they were a phpBB forum, how big were they?)

The size of your package has little to do with how fast your site is. Package size is just the maximum amount of bandwidth and storage you can use.

On a shared system, you only get so much CPU, once you exceed that, you need to move to semi-dedicated or/then dedicated.

Originally Posted by Serra

On a shared system, you only get so much CPU, once you exceed that, you need to move to semi-dedicated or/then dedicated.

Yes, that's what I meant: does anyone have any experience with how big and active a phpBB forum tends to be before they are forced to move to a semi-dedicated or dedicated server?

Are we talking like 50 concurrent users or 500 or 5000?

(Sadly, my current host uses some strange controlpanel rather than cPanel so I can't tell how busy the server is. Chalk that up as reason #4 why I'm shopping for a new web host.)

[Pitrow]

I have a slightly smaller PhpBB running on one of my accounts: 26000 articles ('cause I prune often), 1400 total users, 51 max online users, typical concurrent number of users is 10 in the winter and 20 in the summer. I haven't had any problems so far (knock on wood).