I run a 4,000 member board with 300+ users online at any given time on average. I've been forced to disable search because of the performance hit the server takes when people use it.

Is there any way to optimize search, replace search, or somehow improve the search function of vbulletin 2.2.6?

The hardware the box is currently running on isn't the best, but I think it's held up very well considering the loads.

Thank you for any assistance you can provide. I will post any diagnostic information if it is required.