A Quad Channel 4Gb fibre channel PCI Express card is required to connect Xserve RAID to a Mac Pro or Xserve (Intel-based) with a PCI Express bus. The fibre channel PCI Express card is installed in your computer and the cables are used to connect to the SFP port on Xserve RAID with SFP connectors. This card runs at full bandwidth in an eight-lane PCI Express slot. A quad-channel card is ideal if your computer is slot-constrained or if you want to connect two Xserve RAIDs to a single host computer without the expense or complexity of connecting through a Fibre Channel switch. Some hosts can utilize two quad-channel cards and support up to four Xserve RAIDs.