If I Made 300 Nodes In My Community ? Then Will Speed Be Effected. Slow And Slower Than I Made 150 Nodes ?
I think you should set it lower. With amount of big nodes, your forum will be very slow loading until you have a good network or server and trying to optimize it.
Load speed won't be measurably changed. Although if you are asking *if* you should have 300 or 150 nodes, I suspect you probably don't need them. If you don't need them, it's pointless to create them. No one wants to see 300 (or even 150) empty forum nodes. Creating a forum category/node does not make people want to post in it if that's what you are thinking. Take this site for example, we have 142 nodes, but we also have 18.5 million posts to support that many nodes.
This is a good addon if you have alot of forums. http://xenforo.com/community/resources/forum-jump-menu-by-waindigo.2391/ 300 sure sounds like too many.