10 Gigabit Ethernet PHY vs 40 Gigabit Ethernet PHY vs 100 Gigabit Ethernet PHY

This article breaks down the differences between 10, 40, and 100 Gigabit Ethernet physical layers (PHYs). As we know, the physical layer is in charge of handling the physical medium, data rate, and distance requirements of any network.

It also provides error detection and correction, ensuring a reliable connection between devices. This layer can be implemented using wired or wireless connections.

Ethernet Basics

Here’s a quick overview of related Ethernet topics:

• Ethernet over copper
• Business Gigabit Ethernet
• 40Gbps Ethernet PHY
• 100Gbps Ethernet PHY
• 10Gbps Ethernet PHY
• Ethernet types

10 Gigabit Ethernet PHY

10 Gigabit Ethernet operates at approximately 10 Gigabits per second. Almost all optical, copper, and backplane links for 10 Gigabit Ethernet can be divided into two main families:

• 10GBASE-X family: Uses four lanes at 3.125 Gbps.
• 10GBASE-R family: Uses a single lane at 10.3125 Gbps.

For a deeper dive, check out the differences between 10GBASE-T, 10GBASE-R, 10GBASE-X, and 10GBASE-W physical interfaces.

40 Gigabit Ethernet PHY

This type of Ethernet operates at 40 Gigabits per second. 40 Gigabit Ethernet supports five port types, accommodating link distances from 1 meter to 10 kilometers.

All 40 Gigabit Ethernet links use 40GBASE-R encoding over four lanes with 64B/66B scrambled encoding. The two electrical links are 40GBASE-KR4 and 40GBASE-CR4, while the optical links are 40GBASE-SR4, 40GBASE-LR4, and 40GBASE-FR.

100 Gigabit Ethernet PHY

As the name suggests, this Ethernet type operates at 100 Gigabits per second. Like 40 Gigabit Ethernet, 100 Gigabit Ethernet uses electrical lanes of 10 Gbps with scrambled encoding to achieve 100 Gb/s links.

• 100GBASE-CR10: Supports links up to 7 meters over 10 pairs of copper wires in each direction, typically using a jumper cable assembly.
• 100GBASE-SR10: An optical link using short-wavelength lasers with 10 parallel fibers in each direction, supporting short-reach link distances up to 100 meters on OM3 fiber or 150 meters on OM4 fiber (on engineered links).

Quick Comparison