3D Chip Stacking Has a Warpage Problem — GNNs and RTX 4060 Benchmarks Show Why

3D Chip Stacking Has a Warpage Problem — GNNs and RTX 4060 Benchmarks Show Why Three Physical Walls Facing Semiconductor Scaling — It's Not Just One Problem I first heard "Moore's Law is dead" around 2016. Ten years later. The supposedly dead law keeps getting resuscitated by TSMC — N2 mass production hit in late 2025, and N14 (1.4nm generation) is now a credible 2027 roadmap item. But I'll be blunt. The scaling problem is no longer about transistor density. The real walls are three layers deep: Thermal wall — Stack chips and the heat escape paths vanish Power wall — Voltage scaling is approaching hard limits, leakage current keeps climbing Bandwidth wall — Compute performance grows but memory can't keep up I have both an RTX 4060 (272 GB/s) and an M4 (~273 GB/s unified) on my desk, and I run local LLMs through llama.cpp on both. From that firsthand experience — bandwidth starvation is already happening. And a paper that hit ArXiv two weeks ago elegantly exposed part of its structural