Depends on how much your memory you have in server
then you can try optimize apache
with how many "worker threads
" are allowed to run httpd service so you can spread the workload on many instances of httpd (I see you have only 7 listed in your top output)
which on my server is around 20 (with 4GB RAM).
If you have a "heavy" application working on your server (many connections, maybe PHP/MySQL CMS systems (joomla) then it's a hard nut to "crack" to get optimized.
It also depends how many CPU cores you have available (servers often have Xeon CPU's with 4 cores or more and 8 GB RAM and more)