MyBB Community Forums

Overload and error 503

MyBB:1.4.13
MySQL, Postgre:5077
PHP:5213
www.maniakowo.pl
MochaHost

Hello, I decided to write because I really do not know what to do.
I had a forum on the engine MyBB, server home.pl. Site of the beautifully acted, it was almost 1000 users, chat, basic plugs, a lot of departments and posts. And suddenly was error 503, and "retry action" to chat. It was every time.We thought that it was home.pl, so we moved on MochaHost-plan for businesses, unlimited space, etc. We decided create new forum on a new server -and yesterday was 80 registered users. Suddenly provider close forum ,coz we overload, I got an email from the provider -

Quote:Your hosting account has been investigated by our administrators due to
excessive load/high resource utilization which includes high CPU utilization and memory consumption.
We have determined that based on the excessive resource utilization your
account is not a good fit for our shared hosting environment.

and the only thing we can do is buy a dedicated server.
Please, tell me what WE did wrong, why is this so?
I will be grateful for any hint.
Sorry for my eng

That chat probably wouldn't have helped. Nor really much we can do, if your host thinks the load is too high, you'd need to upgrade the account.