Chapter 8 Hardware Acceleration : Hardware acceleration overview : Network processors (NP1, NP2, NP3, NP4 and NP6)
  
Network processors (NP1, NP2, NP3, NP4 and NP6)
FortiASIC network processors work at the interface level to accelerate traffic by offloading traffic from the main CPU. Current models contain NP4 and NP6 network processors. Older FortiGate models include NP1 network processors (also known as FortiAccel, or FA2) and NP2 network processors.
The traffic that can be offloaded, maximum throughput, and number of network interfaces supported by each varies by processor model:
NP6 supports offloading of most IPv4 and IPv6 traffic, IPsec VPN encryption, CAPWAP traffic, and multicast traffic. The NP6 has a capacity of 40 Gbps through 4 x 10 Gbps interfaces or 3 x 10 Gbps and 16 x 1 Gbps interfaces. For details about the NP6 processor, see “NP6 Acceleration” and for information about FortiGate models with NP6 processors, see “FortiGate NP6 architectures”.
NP4 supports offloading of most IPv4 firewall traffic and IPsec VPN encryption. The NP4 has a capacity of 20 Gbps through 2 x 10 Gbps interfaces. For details about NP4 processors, see “NP4 Acceleration” and for information about FortiGate models with NP4 processors, see “FortiGate NP4 architectures”.
NP2 supports IPv4 firewall and IPsec VPN acceleration. The NP2 has a capacity of 2 Gbps through 2 x 10 Gbps interfaces or 4 x 1 Gbps interfaces.
NP1 supports IPv4 firewall and IPsec VPN acceleration with 2 Gbps capacity. The NP1 has a capacity of 2 Gbps through 2 x 1 Gbps interfaces.
The NP1does not support frames greater than 1500 bytes. If your network uses jumbo frames, you may need to adjust the MTU (Maximum Transmission Unit) of devices connected to NP1ports.Maximum frame size for NP2, NP4, and NP6 processors is 9000 bytes.
For both NP1 and NP2 network processors, ports attached to a network processor cannot be used for firmware installation by TFTP.
 
Session that require proxy-based and flow based security features (for example, virus scanning, IPS, application control and so on) are not fast pathed and must be processed by the CPU.