Onboard ethernet versus Intel NIC

Solution 1:

There isn't a difference in latency between onboard and dedicated NIC. Both of these use the PCI-express. Likely the dedicated NIC will be connected to internal PCI-e controller in CPU. Onboard integrated NIC can be connected to the chipset integrated conntroller, not directly to the CPU. But the difference in latencies of transmit data from NIC to memory is almost absent.

If you really care about performance and latency of processing, check next points:

• NICs uses the DMA to transmit data to the main memory, so use the memory with highest frequency
• Newer version of PCI-e is better (more speed - less time for transmit data)
• CPU freq is more important than number of cores.
• In NUMA systems the data should be processed at a local node.
• Don't forget disable the power-saving features
• Use the software with the kernel-bypass like Intel DPDK
• Read about Smart-NIC or FPGA-based DPU to offload the processing