Performance reduction for NP6 processors with 1Gbps interfaces

Due to NP6 internal packet buffer limitations, performance can be reduced for some traffic mixes accelerated by an NP6 processor when both ingress and egress interfaces are 1Gbps interfaces. If you experience a performance reduction when using this configuration, you may be able to improve performance by disabling NP6 acceleration. You can also improve performance by using higher capacity interfaces for example, using 10Gbps interfaces as the ingress and egress interfaces.

This performance problem is most commonly seen on FortiGates with NP6 processors and no internal switch fabric (for example the FortiGate 500E and 600E). The problem is less likely to occur if your FortiGate has an ISF. On a FortiGate 500E and 600E, using the 10Gbyte X1 and X1 interfaces as the ingress and egress interfaces with NP6 offloading enabled results in the expected performance.