Turning Forum off for certain usergroups

[محروم.كوم]

Hi there,

I am on a shared host with an expected rise in bandwidth coming up in the Summer months (active users online). Is there a way to turn off the forums only allowing the paid usergroups to access the site at that time, to limit the server going down or speed problems?

Also, at what point do you think (as far as members on at once) I should be switching to a VPS or Dedicated? Is there a magic number that will bring you down on a shared server? __DEFINE_LIKE_SHARE__