Difference between System, User and I/O wait CPU Consumption

Updated May 18, 2018

User CPU vs. System CPU vs. I/O Wait CPU

CPU utilization is typically separated in system CPU, user CPU and I/O wait CPU consumption:

CPU utilization type	Description
User CPU:	CPU consumption originating from coding outside of the operating system kernel, e.g.: Expensive operation in SAP HANA like scan of large table or counting a high amount of distinct values Expensive operation of non-SAP HANA product running on same host
System CPU:	CPU consumption originating from the operating system kernel, e.g.: Operating system background activities like memory defragmentation Implicit OS calls of SAP HANA like active waits for locks or I/O requests
I/O Wait CPU:	CPUs waiting for I/O requests to complete, can usually be considered as idle time.