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.
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Nvidia's Groq 3 low-latency inference accelerators — which Nvidia calls LPUs — are designed to offer significant inference performance with extremely low latency, as it mainly relies on internal SRAM, which is by definition faster, lower latency, and lower power than any type of DRAM. For example, Nvidia's LP30 processor comes with 512 MB of SRAM and offers 1.23 FP8 PFLOPS performance, or 9.6 PFLOPS per Groq 3 LPX compute tray or 315 FP8 PFLOPS per rack. By contrast, the Rubin CPX accelerator was to deliver up to 30 NVFP4 PetaFLOPS of compute throughput, but with considerably higher latency.
For now, it remains to be seen whether Nvidia will actually offer its Rubin CPX accelerators or will refocus its efforts to Groq 3 LPU low-latency inference accelerators. Given Nvidia's recent $20 billion non-exclusive license acquisition of startup Groq's chip tech and talent, the move would make sense. The lack of Rubin CPX in roadmap slides and publicly favoring LPU processors is a rather clear indicator of the company's priorities. Nonetheless, it is possible that some of Nvidia's customers will deploy its CPX accelerators, as they have already invested in their deployment by tweaking their software for these processors. After all, off-roadmap parts are pretty common in the industry.
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