I am a web programmer and I've been involved in net-based forum administration primarily. Sorry to break the news, but getting a fast server will not help much at all. It may make a small difference, but nothing too noticeable.
The issue is the forum code itself. It is not built to sustain a huge amount of activity at once. In order to increase the speed here at LSD, and sustain it as a viable resource in years to come, LSD must upgrade its technology.
I'd recommend getting a new forum program, and I'll provide you with some recommendations if the admin PMs me. You'll need a database that is built to allow hundreds of members and guests the freedom to browse all at once, without compromising speed.
In addition, some of the newer programs out there will also provide the administrator with the capability to have more banning options, manage banners in a more effective way, set different stratae of user groups for the various sub-forums, and provide the members here with more control-panel options.
A move like this would cost a little under $200, but it would be well worth it. You could also have options set up in such a way as to minimize your problems with "trolls", manage problematic members with new suspension options, and send out newsletters.
Like I said, I have a ton of experience in this area so just let me know how I can help. LSD is a great place, and I'd be willing to chip in for the sake of the community.