​Check CPU Utilization

You should check CPU utilization while I/O is active. CPU utilization per core is more relevant to performance than overall CPU utilization, since it provides an idea of the CPU utilization per network queue.

If you have only a few threads running network traffic, you might only have a few cores being used. However, if those cores are at 100%, your network throughput might be limited by CPU utilization.

In this case, it is time to:

• ​​Tune interrupt the moderation rate as detailed in ​Interrupt Moderation Rate.
• ​​Increase the number of application threads to spread out the CPU load over more cores. If all cores are running at 100%, your application might be CPU bound rather than network bound.

To check CPU utilization (per Core) using Task Manager:

1. ​Open Windows Task Manager and select the Performance tab.
2. ​View the CPU statistics window to observe which cores are being used while traffic is running.
3. ​View the percent utilization for each core.