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Samsung is expected to more than double output of its HBM4 and HBM4E DRAM

562 points · 458 comments · giuliomagnifico

fooker · 1789929721 · focus · HN ↗
What's the main blocker (other than the current inflated cost) for using HBM instead of DRAM as the primary memory for consumer electronics?
1. bob1029 · 1789930366 · focus · HN ↗
  It's not that there's a blocker. It's that it takes roughly 3x the manufacturing capacity to produce an HBM package at the same storage capacity as DRAM. We are sacrificing total bytes for bandwidth.
  1. tliltocatl · 1789931127 · focus · HN ↗
    How so? FEOL is pretty much the same, BEOL is almost the same save TSVs, the packaging tech is different and more advanced, but not exactly 1:1 comparable. Do TSVs really occupy 3x the area of DDR IO's?
    Const-me · 1789931864 · focus · HN ↗
    See remark on the slide 11: <a href="https://www.servethehome.com/micron-evolving-memory-architectures-for-ai-at-hot-chips-2026/" rel="nofollow">https://www.servethehome.com/micron-evolving-memory-architec... That presentation is by Micron.
    Karliss · 1789933718 · focus · HN ↗
    It doesn't really say that it needs to use 3x more area, but that 3x more gets consumed due to "advanced packaging and manfuacturing complexity". Which doesn't properly explain why it consumes 3x more and could simply mean they have a bad yield and 2/3 produced is garbage.
    crote · 1789981224 · focus · HN ↗
    You make HBM by stacking a whole bunch of dies on top of each other. The signals from the upper dies need to pass through vias in the lower dies to get out - taking up valuable die space in a way which simply isn't needed with regular DDR. Similarly, HBM has a far wider bus, so each individual die has, say, 16 banks of depth 32, rather than 4 banks of depth 128. That's more control area needed per byte of memory.
    Those two combined already result in a huge reduction in bytes per mm2, so with the same wafer processing capacity you're producing far less byte of memory. Add to that a complicated chain of HBM-specific packaging steps, and you're now also losing a decent bunch of perfectly-fine dies because rather than putting it into DDR you tried making a HBM sandwich and screwed up.
    Even if the memory cells are the same and have an absolutely identical yield, HBM will always end up having a significantly lower output. That's just the cost of stacking, but some people are willing to pay the per-gigabyte price penalty in return for the higher bandwidth.

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