PCIe 2.0 vs PCIe 3.0 vs PCIe 4.0 vs PCIe 5.0 | Difference between PCIe 2.0 PCIe 3.0 PCIe 4.0 PCIe 5.0

This page compares PCIe 2.0 vs PCIe 3.0 vs PCIe 4.0 vs PCIe 5.0 and mentions difference between PCIe Gen 2, PCIe Gen 3, PCIe Gen 4 and PCIe Gen 5. PCI-e or PCIe stands for Peripheral Component Interconnect Express.

Introduction:
• PCI-e or PCIe stands for Peripheral Component Interconnect Express.
• It is high speed serial computer expansion bus which is designed to replace PCI/PCI-X.
• As mentioned PCI express is successor to traditional PCI interface used in desktop PCs.
• PCI express evolutions are PCIe 1.0, 2.0, 3.0, 4.0, 5.0 and 6.0 (planned).
• These versions support different raw data rates (or speed) and bandwidths.
• It supports maximum data rate of 32 GT/s and interconnect bandwidth of 32 Gb/s.
• It is serial interface unlike PCI which was parallel interface.
• PCI express supports more number of devices (~32) on each bus compare to PCI (~5).

The PCIe interface supports hot plugging and uses point to point or shared switch topology. The figure depicts serial interface connection used by PCIe devices to communicate with the switch.

PCIe 1.0 | PCIe Gen 1 interface

Following are the features of PCIe 1.0 or PCIe Gen 1 interface type:
• Introduced in the year 2003.
• PCIe 1.0 uses line code 8b/10b.
• It supports transfer rate of 2.5 GT/s (~2.5 Gbps). Transfer rate is encoded serial bit rate.
• It supports interconnect bandwidth of 2 Gb/s.
• It supports throughput of 250 MB/s. Throughput is pre-coded data rate prior to encoding. Throughput is also called "Bandwidth Lane Direction".
• It supports total bandwidth for x16 link of ~8 GB/s.

PCIe 2.0 | PCIe Gen 2 interface

Following are the features of PCIe 2.0 or PCIe Gen 2 interface type:
• Introduced in the year 2007.
• PCIe 2.0 uses line code 8b/10b.
• It supports transfer rate of 5.0 GT/s.
• It supports interconnect bandwidth of 4 Gb/s.
• It supports bandwidth lane direction of ~500 MB/s.
• It supports total bandwidth for x16 link of ~16 GB/s.

PCIe 3.0 | PCIe Gen 3 interface

Following are the features of PCIe 3.0 or PCIe Gen 3 interface type:
• Introduced in the year 2010.
• PCIe 3.0 uses line code 128b/130b.
• It supports transfer rate of 8.0 GT/s.
• It supports interconnect bandwidth of 8 Gb/s.
• It supports bandwidth lane direction of ~1 GB/s.
• It supports total bandwidth for x16 link of ~32 GB/s.

PCIe 4.0 | PCIe Gen 4 interface

Following are the features of PCIe 4.0 or PCIe Gen 4 interface type:
• Introduced in the year 2017.
• PCIe 4.0 uses line code 128b/130b.
• It supports transfer rate of 16.0 GT/s.
• It supports interconnect bandwidth of 16 Gb/s.
• It supports bandwidth lane direction of ~2 GB/s.
• It supports total bandwidth for x16 link of ~64 GB/s.

PCIe 5.0 | PCIe Gen 5 interface

Following are the features of PCIe 5.0 or PCIe Gen 5 interface type:
• Introduced in the year 2019.
• It is backward compatible with previous PCIe Gen 1/2/3/4.
• PCIe 5.0 uses line code 128b/130b.
• It supports transfer rate of 32.0 GT/s.
• It supports interconnect bandwidth of 32 Gb/s.
• It supports bandwidth lane direction of ~4 GB/s.
• It supports total bandwidth for x16 link of ~128 GB/s.

What is Difference between other interface types

Useful Interface types

RF and Wireless Terminologies