AMD MI455X: Can a 2nm Process Gamble Shake NVIDIA's Moat?

First, let's look at some data: The MI455X showcased by AMD on July 24, 2025, uses TSMC's 2nm process, integrates 320 billion transistors, comes with 432GB of HBM4 memory, and its single-chip AI compute power is expected to be more than 2.5 times that of the previous generation MI300X. Meanwhile, NVIDIA's Blackwell B200 uses TSMC's 4nm process, has about 208 billion transistors, and 192GB of HBM3e memory. On paper, the MI455X leads across the board in transistor density, memory capacity, and process node. But does this mean AMD can truly challenge NVIDIA's dominance in the AI training market? We need to break this down from three dimensions: technical roadmap, ecosystem barriers, and cost structure.