PCIe 5.0 vs PCIe 6.0 | Difference between PCIe 5.0 and PCIe 6.0

This page compares PCIe 5.0 vs PCIe 6.0 and mentions difference between PCIe 5.0 and PCIe 6.0.

• PCI-e stands for PCI Express which is successor to PCI and PCI-X bus.
• It uses serial connection unlike PCI which uses parallel connection.
• PCI express evolutions are PCIe 1.0, 2.0, 3.0, 4.0, 5.0, 6.0 and 7.0 (Planned for 2025).
• Let us compare PCIe 5.0 vs 6.0 with respect to line code, transfer rate, bandwidth etc.

PCIe, PCI Express

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 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.

PCIe 6.0 | PCIe Gen 6 interface

Following are the features of PCIe 6.0 or PCIe Gen 6 interface type:
• It has been introduced in the year 2021.
• PCIe 6.0 is backward compatible with previous PCIe generations.
• PCIe 6.0 uses flow control units with fixed size (Flits), which allow the use of lightweight FEC with PAM-4 (four level pulse amplitude modulation) and a strong CRC with no impact to latency instead of NRZ modulation (which uses two levels of signaling).
• FEC increases data integrity and two bits are transferred per transfer due to PAM-4.
• It supports transfer rate of 64.0 GT/s which is about 128 GB/s in each direction in 16-lane configuration.
• It supports total bandwidth for x16 configuration link of ~256 GB/s. Due to FEC, net bandwidth is not exactly doubled than PCI 5.0 version.

Difference between PCIe 5.0 and PCIe 6.0

Following table mentions difference between PCIe 5.0 and PCIe 6.0 types with respect to various parameters.

Specifications PCIe 5.0 PCIe 6.0
Data Transfer Rate 32 GT/s per lane 64 GT/s per lane
Aggregate Bandwidth(x16) 128 GB/s 256 GB/s
Additional features Improved Equalization, and advanced error correction PAM4 (Pulse Amplitude Modulation with 4 levels), Forward Error Correction (FEC) improvements, lane margining, and jitter specifications
Applications Advanced computing, AI, machine learning, high-speed networking Data centers, high-performance computing (HPC), AI/ML, IoT, advanced storage solutions
Power efficiency Good Better than PCI 5.0 version
Release year 2019 2021

Conclusion : PCIe 5.0 and PCIe 6.0 are successive generations of the PCI Express interface standard, designed to enhance data transfer rates and overall performance in computer systems. Both generations maintain backward compatibility with earlier PCIe versions and incorporate improvements in efficiency, signal integrity, and error correction mechanisms. PCIe 5.0 and 6.0 cater to the increasing demands of high-performance computing, artificial intelligence, and advanced storage solutions, with PCIe 6.0 particularly poised to address the evolving requirements of modern computing environments.

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