I'm running vBulletin on a RaQ4 with 256 mb of ram. I noticed today that the server load hit 6.5 with about 50 users online.

What can I tweak to get more out of the server??

Or do I just need to upgrade to 512?

Thanks

these might help you out a bit.

vbulletin + mysql
http://i4net.tv/marticle/get.php?action=getarticle&articleid=3

more vbulletin + mysql (scroll towards the bottom)
http://www.webhostingtalk.com/showthread.php?s=&threadid=20454&highlight=tweak+mysql