The Cisco Nexus NXN-K35-2X, K35-S FPGA ( (Field Programmable Gate Array) SmartNIC is a 10Gbps PCI Express network interface card specifically optimized for low-latency environments. On an Intel® Ivy Bridge test system, median latency from application to network to application is 780 nanoseconds for small packets. Half-roundtrip TCP latencies are as low as 930 nanoseconds for small payloads. In addition to a standard Linux driver, a transparent TCP and UDP acceleration library is included, as well as a library for low-level access. With the optional firmware development kit, it is even possible to extend the Cisco Nexus K35-S FPGA SmartNIC firmware and add your own logic to the onboard FPGA. Built-in timestamping functionality records each frame’s arrival time to within 6.2ns. Additionally, the Cisco Nexus K35-S FPGA SmartNIC has Pulse-Per-Second (PPS) input and output and supports hardware-accelerated PTP. These can be used to synchronize the ExaNIC clock to external time references (such as a GPS receivers), allowing users to meaningfully compare captured timestamps across multiple servers and geographic locations. Finally, flow steering can be used to deliver packets to the right application’s receive buffer, while flow hashing can be used to distribute packets across multiple CPU cores for demanding capture applications. The Cisco Nexus K35-S FPGA SmartNIC includes integrated support for bridging, which can further reduce latency by hundreds of nanoseconds. The bridging feature allows the most latency-critical server to be directly connected to the upstream connection. Packets not destined for the local server can be bridged to the second port, transparently and with low latency. This port could be connected to a backup server or to a downstream switch.