Oculink Overview

What is Oculink?

• Purpose: An open standard PCI Express connector with a compact form factor.
• Comparison: Created to compete with Thunderbolt and USB.
• Naming Origin: Initially envisioned as a combination of copper and optical fiber. "CU" comes from copper's chemical symbol.

Development and Features

• Developer: Developed by PCI-SIG, the organization behind PCI interface standards.
• Versions:
  • Latest version, Oculink 2.0, launched in 2017.
  • Supports up to four PCIe 4.0 lanes, with up to 8 Gbps per lane, totaling 64 Gbps.
  • An eight-lane version is available, outperforming Thunderbolt 3 and 4.

Advantages

• Performance: Higher data transfer speed than Thunderbolt 3 or 4, rivaling the upcoming Thunderbolt 5.
• Cost-Effectiveness: Uses cheaper components and requires less manufacturing precision compared to Thunderbolt.
• Consumer Applications: Bridges the performance gap between internal and external GPUs.

Limitations

• Hot-Plugging: Lacks solid hot-plug support; system shutdown is recommended before swapping components.
• Functionality: Only transfers data, requiring at least two cables for device power and connection.

Comparison with Thunderbolt

• Functionality: Thunderbolt integrates video, power, and data transfer, whereas Oculink is data-only.
• Compatibility: Thunderbolt ports are compatible with USB-C cables.
• Adoption: Thunderbolt has broader consumer adoption due to easier usability and Intel backing.

Future Prospects

• Thunderbolt 5: Aims to combine convenience with higher data transfer speeds.
• Improved Oculink Versions: Potential for specialized connectors to perform better as connectors continue to be a bottleneck.

Conclusion

Oculink offers high-performance data transfer at a lower cost but lacks some convenience features found in Thunderbolt, such as hot-plugging and multifunctionality. There's potential for future iterations or new connectors to further refine and specialize data transfer capabilities.