The EP8641A board is available in several Backplane Fabric Configuration options:

S1 - GigE on AMC Ports 0-1, 3.125Gbps SRIO 4x, on AMC Ports 4-7
S2 - GigE on AMC Ports 0-1, 3.125Gbps SRIO 4x, on AMC Ports 8-11
E1 - GigE on AMC Ports 0-1, 2.5Gbps PCI-Express x4 on AMC ports 4-7, 2.5Gbps SRIO 4x on AMC ports 8-11
E3 - GigE on AMC Ports 0-1, 2.5Gbps PCI-Express x8 on AMC ports 4-11

You may also specify bezel size (full or mid) and stand-alone mode, AMC, or both in the checkout notes. Stand-alone boards include a cooling fan and external power supply.