One thing that caught our attention during Jensen Huang's keynote at GTC 2026 on Monday was the lack of any mention of the Rubin CPX context phase accelerator that the company promoted last year as an important part of the Vera Rubin platform. The Rubin CPX was also absent from the slides demonstrated during the keynote, but the slides mention Nvidia's upcoming Groq 3 LPU processors and LPX racks, which may indicate that these processors are replacing the CPX in Nvidia's roadmap.
Nvidia's Rubin CPX GPU was meant to be a part of the company's Vera Rubin and Vera Rubin Ultra platforms. These GPUs were designed to accelerate an initial compute-intensive context phase of a query that processes the input to generate the first output token. The main advantage of the context phase accelerator was its reliance on GDDR7 memory, which does not offer extreme bandwidth like HBM3E or HBM4 but consumes dramatically less power, which was said to greatly improve the competitiveness of Nvidia's Rubin platform for inference workloads.
