[JohnBee]

There are many factors which directly affect your servers capacity as well.

Ideally, you would dedicate a *dedicated server for db processes, and host the remaining data onto a simpler account or across multiple accounts. If you do a search on this forum, you will find multiple threads and modifications to help offload processes and functions over multiple accounts also.

Furthermore, a fast SCSI HD setup and ample memory will help cope with higher loads. Without ignoring the importance of OS optimization, since it has been stated many times, that even the most powerful server will fall to it's knee's without proper optimization.

And what of the CPU? is it 64bit, multi-core etc etc?
64bit OS's have proven to deal with higher memory loads than there 32bit counterparts.

There are a number of other options you could look into to help cope with high loads also, however those mentioned come to mind early on.

Another good idea may be in the planning process as well. In other words, planning for scalability. Depending on your budget and objectives, load balancing and clustering may be the solution to your needs as your project continues to grow.

My advice to you, would be to hit the official vbulletin website www.vbulletin.com and dig around under the *server /hosting forum. There are numerous threads that cover this issue in detail. You will most likely find plenty of helpful information to help you decide what options are viable for you.