This article briefly describes gigabit Ethernet as implemented on the Power Mac G4 (Gigabit Ethernet) computer.

What is it?
Gigabit Ethernet is a standard developed by the Gigabit Ethernet Alliance, and defined by the IEEE 802.3 committee. The aim of this standard is to utilize existing local area network infrastructure to achieve up to 1 gigabit per second (1 Gbps) transfer rates. This is why gigabit Ethernet utilizes Category 5 or better unshielded twisted pair cabling (UTP), and the RJ-45 connector that is used in 10/100 megabits per second (Mbps) networks.

To achieve maximum transfer rates from gigabit Ethernet capable hardware, you also need to install gigabit Ethernet compliant switches, hubs, and routers. Otherwise, the Power Mac G4 (Gigabit Ethernet) computer switches to a 10 Mbps or 100 Mbps transfer rate depending upon the network hardware that is used.

To utilize gigabit Ethernet, you must use an Ethernet cable with all eight wires (four pairs) present. If you use an inexpensive two pairs-wired cable, the maximum connection speed can only be 100 Mbps.

How to determine connection speed
Open Apple System Profiler by choosing it from the Apple menu. Click the disclosure triangle next to "Network overview" to reveal speed (10 Mbps, 100 Mbps, or 1 Gbps) and duplex information (half- or full-duplex).

Using a crossover Ethernet cable
Connecting two gigabit Ethernet capable computers together via Ethernet can be accomplished with a standard four pair category 5 or better Ethernet cable. No crossover cable is necessary.

Connecting a gigabit Ethernet capable computer to a non-gigabit Ethernet computer requires a crossover cable.