Core Viewpoint - The introduction of NVIDIA's Rubin CPX GPU, which opts for GDDR7 memory instead of the traditional HBM, raises questions about the future of HBM in AI applications and its potential threats from more cost-effective memory solutions [1][7]. Group 1: Rubin CPX GPU Overview - The Rubin CPX GPU was launched on September 10, 2023, specifically designed for long-context AI workloads, emphasizing a new inference acceleration concept called "disaggregated inference" [2]. - This GPU is not a simplified version of the standard Rubin GPU but is deeply optimized for inference performance, indicating a shift in focus from training to inference in AI applications [2][4]. - The Rubin CPX GPU is expected to provide up to 30 PFLOPs of raw computing power with 128 GB of GDDR7 memory, contrasting with the standard Rubin GPU's 50 PFLOPs and 288 GB of HBM4 memory [3]. Group 2: Architectural Differences - The architectural differences between Rubin CPX and standard Rubin GPU highlight a focus on task specialization, with Rubin CPX handling context construction and Rubin GPU managing generation tasks [5][9]. - The overall performance of the system with Rubin CPX is projected to reach 8 ExaFLOPs NVFP4, significantly surpassing previous models [4]. Group 3: Memory Transition and Implications - The shift from HBM4 to GDDR7 is driven by the need to reduce costs while maintaining performance, as GDDR7 provides sufficient bandwidth for the context-building tasks of the Rubin CPX GPU [9]. - This transition is expected to lower the total cost of systems, making AI infrastructure more accessible to a broader range of enterprises [9]. - The demand for GDDR7 is surging, with NVIDIA increasing orders from suppliers like Samsung, which is expanding production capabilities to meet this demand [10][12]. Group 4: Market Dynamics and Future Outlook - The introduction of GDDR7 is seen as a potential threat to HBM, but it also opens new opportunities for memory suppliers, particularly Samsung, which is poised to benefit from increased orders [10][12]. - SK Hynix has announced the completion of HBM4 development, indicating that while GDDR7 is gaining traction, HBM technology continues to evolve and remain relevant in the market [13].