ConnectX-4 from Mellanox is a family of high-performance and low-latency Ethernet and InfiniBand adapters. The ConnectX-4 Lx EN adapters are available in 40 Gb and 25 Gb Ethernet speeds and the ConnectX-4 Virtual Protocol Interconnect (VPI) adapters support either InfiniBand or Ethernet. This product guide provides essential presales information to understand the ConnectX-4 offerings and their key features, specifications, and compatibility. This guide is intended for technical specialists, sales specialists, sales engineers, IT architects, and other IT professionals who want to learn more about ConnectX-4 network adapters and consider their use in IT solutions.