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Apple deploys LPDDR5X for the energy efficiency and cost (lower is better), whereas NVIDIA will always prefer GDDR and HBM for performance and cost (higher is b

• _zoltan_ 10mo ago
  the GH/GB compute has LPDDR5X - a single or dual GPU shares 480GB, depending if it's GH or GB, in addition to the HBM memory, with NVLink C2C - it's not bad!
  • wtallis 10mo ago
    Essentially, the Grace CPU is a memory and IO expander that happens to have a bunch of ARM CPU cores filling in the interior of the die, while the perimeter is all PHYs for LPDDR5 and NVLink and PCIe.
    • _zoltan_ 10mo ago
      fully agree! with MGX and CX8 we see PCIe root moving to the NIC, which is very exciting.
    • rbanffy 10mo ago
      > have a bunch of ARM CPU cores filling in the interior of the die The main OS needs to run somewhere. At least for now.
      • wtallis 10mo ago
        Sure, but 72x Neoverse V3 (approximately Cortex X3) is a choice that seems more driven by convenience than by any real need for an AI server to have tons of somewhat slow CPU cores.
        • _zoltan_ 10mo ago
          there are uses cases where those cores are used for aux processing. there is more to these boxes than AI :-)
          • rbanffy 10mo ago
            If someone gave me one for free, I'd totally make it my daily driver. I don't do much AI, but I always wanted to have a machine with lots of puny cores since the Xeon Phi appeared. The justification is that processors cores aren't getting much faster, but what they are is getting more numerous - entry-level machines have between 4 and 8 cores - and adapting code to run across multiple cores is important if we want to utilise all those cores.
            • _zoltan_ 10mo ago
              anybody writing single core code in 2025 professionally isn't very professional.. the core count doesn't matter. a top of the line Turin system has less than 1.4TB/s memory for the whole dual CPU system. A 2020 era A100 has 2TB/s.
        • deleted 10mo ago
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