What is making this server load?

After server load problems on shared host I finaly moved to a vps to see whats going on on the serverside.
Guaranteed RAM 256 MB
Burstable RAM 1 GB
Got 4 CPUs: Intel(R) Xeon(TM) CPU 3.00GHz cache 1024 KB
I did apache and mysql config tweaks that people advice on forums. And so many optimizations on mysql queries. I think tweaks reduced server load a few but I got this "top" stats:
http://img476.imageshack.us/img476/8954/top8zc.gif

httpd with PID 2240 is making 99% cpu usage average every 5 seconds and mysql going 99% sometimes mostly httpd. Load 7.12 but on cpanel service status about 1.5 at that time. But during high traffic hours it goes 10-15. I got about 8000 unique visitors.

I have to solve this problem. Please help me to find out what is making this cpu load.

 

 

 

 

Top