How much memory does your http/mysql use? Numbers...
 

Ours is this, looks freaking high for the kind of traffic:

httpd httpd (pid 86682 86011 8 ..... 659 76652 ) 5.54 GB Start Stop Restart
mysqld mysqld (pid 84854 ) 1.43 GB Start Stop Restart

Is yours (a lot) higher? What traffic?

it's not much about traffic - it's more about application and optimizations...

What kind of traffic?

Data during peak time isn't representative and both could probably be optimized.

Throwing out httpd and installing a decent webserver like NginX is a good start.