639
Framework’s first desktop is a strange—but unique—mini ITX gaming PC (arstechnica.com)
submitted 2 years ago by to c/technology@lemmy.world
285 comments fedilink hide all child comments
you are viewing a single comment's thread
view the rest of the comments
[–] 2 points 2 years ago* (last edited 2 years ago) (5 children)

The cache hierarchy has flopped? People aren't using swap?

NUMA also hasn't flopped, it's just that most systems aren't multi socket, or clusters. Different memory speeds connected to the same CPU is not ideal and you don't build a system like that but among upgraded systems that's not rare at all and software-wise worst thing that'll happen is you get the lower memory speed. Which you'd get anyway if you only had socketed RAM.

  • permalink
  • fedilink
  • source
  • parent
  • hideshow 5 child comments
    •
  • [–] 2 points 2 years ago (1 child)

    In systems where memory speed are mismatched, the system runs at the slowest module's speed. So literally making the soldered, faster memory slower. Why even have soldered memory at that point?

  • permalink
  • fedilink
  • source
  • parent
  • hideshow 1 child comment
    •
  • [–] 0 points 2 years ago*

    I'd assume the soldered memory to have a dedicated memory controller. There's also no hard requirement that a single controller can't drive different channels at different speeds. The only hard requirement is that one channel needs to run at one speed.

    ...and the whole thing becomes completely irrelevant when we're talking about PCIe expansion cards the memory controller doesn't care.

  • permalink
  • fedilink
  • source
  • parent
  • [–] 2 points 2 years ago (2 children)

    Yeah, the cache hierarchy is behaving kinda wonky lately. Many AI workloads (and that’s what’s driving development lately) are constrained by bandwidth, and cache will only help you with a part of that. Cache will help with repeated access, not as much with streaming access to datasets much larger than the cache (i.e. many current AI models).

    Intel already tried selling CPUs with both on-package HBM and slotted DDR-RAM. No one wanted it, as the performance gains of the expensive HBM evaporated completely as soon as you touched memory out-of-package. (Assuming workloads bound by memory bandwidth, which currently dominate the compute market)

    To get good performance out of that, you may need to explicitly code the memory transfers to enable prefetch (preferably asynchronous) from the slower memory into the faster, á la classic GPU programming. YMMW.

  • permalink
  • fedilink
  • source
  • parent
  • hideshow 2 child comments
    •
  • [–] 1 point 2 years ago (1 child)

    I wasn't really thinking of HPC but my next gaming rig, TBH. The OS can move often accessed pages into faster RAM just as it can move busy threads to faster cores, gaining you some fps a second or two after alt-tabbing back to the game after messing around with firefox. If it wasn't for memory controllers generally driving channels all at the same speed that could already be a thing right now. It definitely already was a thing back in the days of swapping out to spinning platters.

    Not sure about HBM in CPUs in general but with packaging advancement any in-package stuff is only going to become cheaper, HBM, pedestrian bandwidth, doesn't matter.

  • permalink
  • fedilink
  • source
  • parent
  • hideshow 1 child comment
    •
  • [–] 1 point 2 years ago

    The thing is, consumers didn’t push Nvidias stock sky high, AI did. Microsoft isn’t pushing anything sane to consumers, Microsoft is pushing AI. AMD, Intel, Nvidia and Qualcomm are all pushing AI to consumers. Additionally, on the graphics side of things, AMD is pushing APUs to consumers. They are all pushing things that require higher memory bandwidth.

    Consumer will get ”trickle down silicon”, like it or not. Out of package memory will die. Maybe not with you next gaming rig, but maybe the one after that.

  • permalink
  • fedilink
  • source
  • parent