Symptom(s):
High CPU utilization when multiple connections are loaded using the Linux* driver.

Cause:
The CPU utilization can be lowered by tweaking the Interrupt Throttle Register (ITR), best result with ITR =3000.

However this results in throughput loss when fewer ports are active.

Solution:
When e1000 is loaded with default settings and multiple adapters are in use simultaneously, the CPU utilization may increase non-linearly. In order to limit the CPU utilization without impacting the overall throughput, it is recommended to load the driver as follows:

insmod e1000.o InterruptThrottleRate=3000,3000,3000.

This sets the InterrupThrottleRate to 3000 interrupts/sec for the first, second and third instances of the driver. The actual value depends on the platform used.

Operating System:

This applies to: