Astera Labs unveiled an alternative to Nvidia's NVSwitch for building rack-scale AI systems on Tuesday, claiming it will work with nearly any accelerator. The AI fabric switch, codenamed Scorpio X, crams 320 lanes of PCIe 6.0 connectivity into a single ASIC with 5.12 TB/s of bidirectional bandwidth. Historically, PCIe switches have been used in a variety of applications including scale-out compute fabrics. CPUs alone either didn't offer enough or fast enough lanes for all the GPUs, NICs, and storage required. So, rather than hanging everything off the CPU, a PCIe switch, often built into the NIC, was used to connect everything together. Astera contends that with a big enough switch, PCIe is a viable alternative to interconnects like NVLink, in the scale-up fabrics used to make dozens or more GPUs behave more like a single large one without needing to redesign their accelerators. However, Astera hasn't just built a bigger PCIe switch.…