The Combination Card Cage (AD247A) provides two PCI Express x8 slots and one PCI-X 133 MHz 64 bit I/O slot. Please note that the AD247A is required for Windows and Linux-based systems. Each slot of the AD247A has its own dedicated bus and its own independent I/O channel. The two PCI Express slots 2.6 GB/s of sustained bandwidth, while the one 133 MHz slot provides 1.1 GB/s of sustained bandwidth.