The 16-port 10 Gigabit Ethernet copper module provides up to 130 10 Gigabit Ethernet copper ports in a single Cisco Catalyst 6509 Switch chassis and 260 10 Gigabit Ethernet ports in a Cisco Catalyst 6500 Virtual Switching System (VSS) 1440 and is primarily designed for data center access with a secondary use case for switch-to-switch connectivity. It consists of 4 port groups of 4 ports each. Users can operate each port group in either over subscription mode (2 to 4 ports used per port group) or performance mode (1 port used per port group), providing the flexibility to use some ports for connection to servers and other ports for interconnection of switches. In performance mode, up to 4 10 Gigabit Ethernet ports can be used to create a virtual switch link in a VSS.