Getting the Most from Your Cores

Conclusion

CPU utilization charts can be very useful because they visually indicate how heavily a core is utilized. If the utilization is fairly high (close to 100%) but then drops low for a noticeable period of time, something is causing the core to become idle. The reasons for CPU utilization to drop could be from waiting on I/O (reads or writes) or because of network traffic from one node to another (possibly MPI communication).

In a general sense, CPU utilization provides an idea of how well an application is performing and if it is using the cores as it should. Remember, the first two letters in HPC stand for “High Performance.”