This document describes speeds of Ethernet cabling used by Macintosh computers.
Note: This document does not cover the fiber optic Apple Gigabit Ethernet PCI Card. For information on that product, see technical document 58296: "About Your Apple Gigabit Ethernet PCI Card"
Speeds of Ethernet cable
Twisted pair Ethernet cable is available in different grades for different speeds of Ethernet. Your Macintosh computer may use any of the following Ethernet grades:
Your computer's Ethernet speed
You can look up the speed of Ethernet hardware included with your computer by using the Apple Spec Database (http://www.info.apple.com/applespec/applespec.taf).
Determining your network "speed limit"
A Macintosh computer with a higher speed Ethernet adapter may use a slower-rated cable, but transmission speed is limited to the speed of the cable. Conversely, a slower-rated computer may use a faster rated cable but be limited by its own speed. Hubs and routers may also limit speed of network traffic. Be sure to buy Ethernet cable that is appropriate for your networking goals.