Broadcom Launches Taurus BCM83640 A 3nm 400G Per Lane Optical DSP

Why It Matters

The DSP doubles lane bandwidth, allowing AI‑focused data centers to scale compute without hitting optical bottlenecks, accelerating next‑generation high‑density switching architectures.

Key Takeaways

• 3nm DSP enables 400G per lane
• Supports 1.6T transceivers, future 3.2T modules
• Doubles bandwidth density versus 200G lanes
• Simplifies 3.2T optical design, no retimers needed
• Sampling started; mass production slated for late 2026

Pulse Analysis

AI workloads are driving data‑center power and bandwidth demands to unprecedented levels, making the optical interconnect layer a critical choke point. Broadcom’s Taurus BCM83640 addresses this pressure by leveraging a cutting‑edge 3 nanometer process to integrate a PAM4 digital signal processor that can handle 400 Gbps per lane. The monolithic design reduces latency and power consumption while delivering a superior bit‑error‑rate, positioning it as a cornerstone for 1.6 Tbps transceiver modules that will soon become the backbone of hyperscale AI clusters.

The technical architecture of Taurus combines an 8‑to‑4 gearbox PHY with a driver optimized for IEEE‑compliant electro‑absorption lasers and photodiodes. By doubling the per‑lane capacity from the prevailing 200 Gbps, the chip effectively doubles bandwidth density within a standard 1RU switch chassis, enabling a single platform to reach 102.4 Tbps of switching capacity. This streamlined electrical‑to‑optical mapping eliminates the need for complex retimers and gearboxes in upcoming 3.2 Tbps optical modules, simplifying design and reducing bill‑of‑materials costs for OEMs.

From a market perspective, Broadcom’s early‑access sampling signals strong interest from hyperscale operators and networking equipment vendors. The anticipated late‑2026 production ramp aligns with the rollout of 1.6 Tbps Ethernet fabrics, such as Broadcom’s own Tomahawk 6, and sets the stage for the next wave of 204.8 Tbps switches. As AI clusters expand beyond 100,000 GPUs, the Taurus platform offers a scalable, power‑efficient pathway to meet the escalating data‑throughput requirements, potentially reshaping the competitive dynamics of high‑speed optical networking.