Originally Posted by pingpipe
If I were you I'd consider a dual quad core server with at least two hard drives in RAID. Your current server only has one hard drive - that's a single point of failure. If you've got the budget available it would also be worthwhile to think about two servers with load balancing
Could you tell me please which OS supports dual quad core? None, afaik.
Find the bottleneck, hire a system administrator, ask your hosting company...
I run some dedicated servers and I know for sure that there is a bottleneck (most it's disk i/o related).
Check with e.g. top (if you use Debian) and look at your web stats for peak times (while checking with top).
Check your machine config, web server config, Apache module's config's, ...
If you have a lot of database accesses (e.g. when using a CMS), check those configs (e.g. mySQL), use caching (with Apache not a big problem).
Optimize your front-end of the website, combine CSS/JS, use content compression, caching, cookieless domain (watch the URL in my signature)...
There is a lot that can cause it, but 30000 shouldn't be a problem for a XEON machine.