High "Physical Memory Usage"

In cPanel you might see your "Physical Memory Usage" is high - this is a known bug in the UI, 99% of the cases the actual memory usage will be a lot lower.

In Linux, whenever the system read files it will try to put as many of the files in the memory of the server if there's space - this is done to minimize the number of disk reads performed - however, this results in a high "Physical Memory Usage" in cPanel.