Difference between Fast Ethernet and Gigabit Ethernet

Ethernet is a set of protocols that are used primarily in LANs, although they can also be used in larger networks like MANs and even WANs. Ethernet was first standardized in the 1980s as the IEEE 802.3 standard. Since then, it has seen several upgrades and its data carrying capacity kept increasing with each upgrade.

  • Standard Ethernet can support data speeds up to 10 Mbps.

  • Fast Ethernet can carry data at a maximum speed of 100 Mbps.

  • With Gigabit Ethernet, the data speeds reached a maximum speed of 1 Gbps.

  • 10-Gigabit-Ethernet can carry data at incredibly high speeds of 10 Gbps.

Fast Ethernet is a variation of the Ethernet standard that allows data to be transmitted at speeds of up to 100 megabits per second via local area networks (LAN). It debuted in 1995 as the world's fastest network connection at the time and remained the fastest network till the introduction of Gigabit Ethernet.

Gigabit Ethernet is the family of Ethernet technologies that achieve theoretical data rates of 1 gigabit per second (1 Gbps). It was introduced in 1999 and was defined by the IEEE 802.3ab standard.

Read through this article to find out more about Fast Ethernet and Gigabit Ethernet and how they are different from each other.

What is Fast Ethernet?

The IEEE 802.3u standard defines Fast Ethernet, often known as 100-Base-X or 100 Mbps Ethernet. Here, "100" is the maximum throughput, i.e. 100 Mbps, "BASE" denotes the use of baseband transmission, and "X" is the type of medium used.

Fast Ethernet refers to a set of protocols that support and deliver data transmission speeds of 100 Mbps. The cable length was limited to 100 meters in copper-based Fast Ethernet, and multiple cable classifications were supported. Fast Ethernet in fiber mode has a range of 400 yards to up to 25 miles.

Fast Ethernet networks were backward compatible with 10-Base-T networks in every way.

What is Gigabit Ethernet?

Gigabit Ethernet is a variation of the Ethernet technology that allows 1 Gbps transmission of Ethernet frames in local area networks (LANs). Many networks, particularly those of large corporations, use it as a backbone. Gigabit Ethernet is an upgrade to the previous 802.3 Ethernet standards of 10 Mbps and 100 Mbps. It supports 1,000 Mbps bandwidth while remaining fully compatible with the estimated 100 million Ethernet nodes now in use.

Gigabit Ethernet typically uses an optical fiber connection to send data quickly over long distances. Copper cables and twisted pair connections are utilized for short distances.

GbE or 1 GigE is the abbreviation for gigabit Ethernet. Dr. Robert Metcalf created Gigabit Ethernet, which Intel, Digital, and Xerox introduced in the early 1970s. It gradually grew into a wider LAN technology system for global data and information sharing. The IEEE 802.3 Committee certified the first Gigabit Ethernet standard, known as 802.3z, in 1998.

Five physical layer standards support Gigabit Ethernet. The IEEE 802.3z standard includes 1000 BASE-SX for multimode optical fiber data transfer. In addition, the IEEE 802.3z standard offers 1000 BASELX transmission over single-mode fiber and 1000 BASE-CX transmission over copper cabling.

These standards employ 8b/10b encoding, but for transmission over twisted pair cable, IEEE 802.3ab, also known as interface type 1000-BASE-T, has a different encoding sequence.


Fast Ethernet

Gigabit Ethernet


Fast Ethernet is the successor of 10-Base-TEthernet.

Gigabit Ethernet is successor of Fast Ethernet.

Network speed

The maximum speed of Fast Ethernet is 100 Mbps.

Gigabit Ethernet speed can reach up to 1 Gbps.


Fast Ethernet is simple to configure.

Gigabit Ethernet is quite complex to configure.


Fast Ethernet generates ore delay.

Gigabit Ethernet generates less delay than Fast Ethernet.

Coverage Limit

The maximum coverage distance for Fast Ethernet is 10 kilometers.

The maximum coverage distance for Gigabit Ethernet is 70 kilometers.

Round trip delay

The round trip delay in Fast Ethernet is 100 to 500 bit times.

The round trip delay in Gigabit Ethernet is 4000 bit times.


Both Fast Ethernet and Gigabit Ethernet are types of Ethernet standards that are primarily used in LANs to transmit data at high speed. These two standards differ in terms of their maximum data carrying capacity and speed. Fast Ethernet can carry data at a maximum speed of 100 Mbps, while with Gigabit Ethernet, the speeds can go up to 1 Gbps.

Updated on: 06-Jan-2023

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