StarTech.com 1 Port PCI Express 10GBase-T / NBASE-T Ethernet Network Card - 5-Speed Network Support: 10G/5G/2.5G/1G/100Mbps - PCIe 2.0 x4 (ST10GSPEXNB) - network adapter - PCIe 2.0 x4 - 1000Base-T x 1

Add an Ethernet port to a server or workstation, with support for five network speeds: 10G/5G/2.5G/1G/100Mbps. This 5-speed network adapter card offers versatile and cost-efficient network connectivity. It lets you add an Ethernet port to your server or desktop computer and access your network at multiple speeds: 10G, 5G, 2.5G 1G and 100Mbps.
Cost-effective, multimode network connectivity
Designed for low-power, single-port network applications, the PCIe NIC offers a cost-effective and versatile networking solution by providing additional bandwidth to meet your network needs, without having to overhaul your infrastructure wiring. Fully compliant with 10GBase-T and NBASE-T specifications, the network card lets you add an Ethernet port to your server or high-powered workstation through a PCI Express x4 (or higher) slot. (10G network speeds require Cat6a cable. All other speeds require Cat5e cable.)
Advanced technology for optimal performance
The network controller card features advanced NBASE-T technology, supporting the latest multi-gigabit, including new Cisco campus switches and Aruba Networks access points. The card enables you to connect to NBASE-T based equipment at network speeds of 2.5Gbps or 5Gbps, over your existing Cat5e infrastructure, without having to upgrade to more expensive Cat6a.
NBASE-T technology accelerates the speed of twisted pair Cat5e copper cabling over a distance of up to 100 meters. The Ethernet network card also supports the more common 10G over copper, and 1G network connections using existing Cat 6/Cat5e or better cabling.
The 5-speed Ethernet network card is a powerful combination of the Tehuti TN4010 controller and the Marvell 88X3310P transceiver, providing low-power and high-performance NBASE-T solutions. The Tehuti 10GbE controller supports autonegotiation, which ensures the optimal speed over Cat5e/Cat6 is selected: 10GbE, 5GbE, 2.5GbE, GbE or 100Mbps (Fast Ethernet). The network card also offers compatibility with Microsoft Hyper-V virtualization software and iSCSI support to combine LAN and SAN functions.
Operating efficiency and flexible use
The Tehuti TN4010 chipset, compliant with 802.3az Energy Efficient Ethernet, ensures peak operating efficiency with reduced power consumption. The decreased power consumption helps to minimize heat generated by the card, to avoid increasing the operating temperature within your server case.
The network card also supports advanced features including 9K Jumbo Frames and  802.1q VLAN tagging. For additional versatility, the controller card is equipped with a standard profile bracket and includes a low-profile/half-height bracket for installation in small form-factor computers.
The ST10GSPEXNB is backed by a StarTech.com 2-year warranty and free lifetime technical support.