An upgraded form of standard PCI gigabit ethernet cards, the PCI-X gigabit ethernet cards are intended to upgrade Macs for expanded networking capabilities. The PCI-X gigabit ethernet cards are expansion cards which are able to run up to four times the standard clock speed of PCI GbE cards. Available in both hard-wired copper connections and optical connectors, these customizable and tunable network drivers support link aggregation and are designed especially to handle larger transfers. PCI-X gigabit ethernet cards will be perfect for your high-performance business network, and are able to expand the network connectivity for PowerMac systems. PCI-X gigabit ethernet cards work with OSX 10.4.11 and up, and is backwards compatible with virtually all the previous PCI versions.