The group responsible for managing the PCIe specification said when it finalized PCIe 6.0 in 2022 that data centers would be its earliest adopters. The organization's roadmap is beginning to bear fruit as a new fiber-optic connectivity demonstration shows how PCIe 6.0 can scale clusters.
At the end of last month, a customized data center from Nubis Communications and Alphawave Semi demonstrated PCIe6.0 connectivity, with a theoretical bandwidth of 64GT/s. This performance is twice the data transfer rate of PCIe 5.0, which has recently begun to appear in the latest consumer PCs.
At the DesignCon2024 conference held last week, the Tektronix company booth demonstrated the Alphawave PCIe subsystem using PiCORE controller IP and PipeCOREPHY, which sends and receives data at unprecedented speeds through the NubisXT1600 linear optical engine. The test used an optical link, which the demonstrator claimed maintained the same bandwidth as copper cable over longer distances.
The Nubis engine supports 16 PCIe6.0 lanes or Ethernet fiber optic connections, with a speed of 100Gb/s per lane. The increase in bandwidth could allow the two companies to build increasingly larger artificial intelligence and machine learning servers using multiple nodes.
Two years ago, when the PCI-SIG released the final PCIe 6.0 specification, it said the next generation of connectivity would first appear in the enterprise, industrial, automotive, military and aerospace sectors as consumers gradually gain access to PCIe 5.0 components for memory and storage. So far, everything is going according to plan. Consumer PCs won't adopt the PCIe 6.0 specification for several years.
The alliance is currently developing the PCIe7.0 specification. An early draft that emerged last year promised to double data transfer rates again to 128GT/s, enabling 512GB/s bidirectional x16 throughput. In addition to artificial intelligence and machine learning, initial applications may include 800G Ethernet, cloud computing, quantum computing, hyperscale data centers and high-performance computing.
Alphawave and Teledyne LeCroy demonstrated PCIe7.0 related methods at DesignCon using the former's DSP-based serializer-deserializer and the latter's WaveMaster8650HD65GHz, 12-bit high-definition oscilloscope. The demonstration tested transmitter jitter, impulse response and signal-to-noise distortion for the upcoming specification.
The alliance expects to release the final PCIe 7.0 specification in 2025. Hardware supporting PCIe 7.0 may appear in 2027 or 2028. As for when consumer PCs will get it, it's currently unknown.