#hbm
2 articles
01
·Computer Architecture·★ MEMBER·PAPER·9 min read
The GPU Memory Hierarchy — HBM, SRAM, Registers, and Why Movement Wins
What sets a GPU's speed is not the arithmetic units but where the data sits — registers, shared memory, L2 or HBM — and how many times it is moved. Capacities and bandwidths by order of magnitude, arithmetic intensity and tiling, a roofline per level of the hierarchy, and finally FlashAttention: more FLOPs, less time.
02
·Fabrication & Packaging·★ MEMBER·10 min read
Advanced Packaging — How CoWoS and HBM Stacking Became the Bottleneck for AI
What limited the supply of AI accelerators was not leading-edge logic wafers but the step that puts several finished chips into one part. From the reticle limit and the exponential math of yield, through 2.5D interposers, HBM stacks and TSVs, to hybrid bonding and the bill that heat and warpage send back.