Thread

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. nutjob2 · 1789930193 · focus · HN ↗
  Nothing except CPU manufacturer choices. Mac laptops use it and they're consumer products.
  People will have to get used to buying a fixed amount of RAM with their CPU but thats unlikely to be a problem.
  1. fooker · 1789930550 · focus · HN ↗
    Apple's "unified memory" marketing is so strong that even tech literate people seem to have this misconception!
    They have managed to pull this sort of thing off many many times. <a href="https://en.wikipedia.org/wiki/Reality_distortion_field" rel="nofollow">https://en.wikipedia.org/wiki/Reality_distortion_field
    Rohansi · 1789931691 · focus · HN ↗
    Yup, the only reason Macs have higher memory bandwidth is because they use more memory channels, which gives them a wider bus. Both Intel and AMD only allow more than dual channel memory on server class processors these days.
    Kon5ole · 1789932901 · focus · HN ↗
    The memory bandwidth is a small thing compared to the massive win you get by not having to move data between two memory pools at all.
    Rohansi · 1789933929 · focus · HN ↗
    Depends on your workload. And AMD has supported unified memory long before Apple Silicon existed anyway.
    fooker · 1789935147 · focus · HN ↗
    Often you don't move memory around as a programmer, but that's exactly what happens in the background.
    It's the address space that's unified, not always the physical hardware.
    The data movement (when needed) is handled transparently in the background by page faults and other tricks.
    Rohansi · 1789958942 · focus · HN ↗
    Moving memory around is a bottleneck. Non-unified memory usually means copying over the PCIe bus which is way slower than RAM (and way way slower than VRAM). Actually unified memory means you don't need to copy anything at all though which is the absolute best case for performance.
    [deleted] · 1790001137 · focus · HN ↗
    [deleted]

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