Apache High CPU Usage 100%

Most of the time I have found this to be caused by Apache waiting for processes and all the coections getting used up, and you see slow website performance or coection issues. Can be caused my many factors, often from low ram, mysql performance issues (needs optimization), too slow cpu, slow storage system... How much memory does the server have? Is there any swap in use? (

With the latest updates I see no performance issues on any of the servers I manage.