The AMD Epyc 7401P you’re using has 128 PCIe 3.0 lanes, which can provide way more bandwidth than the 4Gbps figure you’re getting (8 Gbps per lane, so 1024 Gbps

The AMD Epyc 7401P you’re using has 128 PCIe 3.0 lanes, which can provide way more bandwidth than the 4Gbps figure you’re getting (8 Gbps per lane, so 1024 Gbps on paper). The AMD Epyc platform has been benchmarked at 57 GBps (bytes, not bits) of random storage bandwidth: http://www.legitreviews.com/one-amd-epyc-processor-reaches-57-gbs-of-random-storage-bandwidth_195653 http://www.legitreviews.com/one-amd-epyc-processor-reaches-5... There’s simply no way a PCIe x4 NIC is going to be able to compete with the bandwidth available within that server.