Following the unveiling of new MacBook Pro models last week, Apple surprised some with the introduction of a base 14-inch MacBook Pro with M3 chip,...

8GB RAM on M3 MacBook Pro ‘Analogous to 16GB’ on PCs, Claims Apple::Following the unveiling of new MacBook Pro models last week, Apple surprised some with the introduction of a base 14-inch MacBook Pro with M3 chip,…

  • @[email protected]English
    6•1 year ago

    Note those are comparing different numbers.

    The number you quoted was for a single memory channel.

    A processor has as many memory channels as it feels like. So that 800 number basically means about 16 channels. The M2 plain seems to be about two channels.

    For comparison, x86 desktop CPUs have long been 2 channel designs. You go up the stack and you have things like EPYC having 12 channels.

    So for single socket design, apple likely has a higher max memory performance than you can do single socket in x86 (but would likely turn in lower numbers than a dual socket x86 box).

    • @[email protected]English
      3•1 year ago

      So to clarify, the M2 Ultra runs at 800 GB/s because it’s utilizing multiple memory channels, which is like running dual/quad/etc. channel RAM in an x86 PC. So at the max 64 GB/s bandwidth of DDR5 ram, you could run quad channel and get 256 GB/s right? And getting up to 12 channels of DDR5 could mean a bandwidth of 768 GB/sec?

      Yeah, in that case Apple is definitely over charging. To be fair, my mb can’t run 12 channels of RAM but it also won’t cost me an arm and a leg and a kidney to have similar performance per GB

      • @[email protected]English
        5•1 year ago

        Note that I can’t think of modem four channel x86. Either they are the usual two channel (two dimms per channel is how four dimm slots are organized) or have way more (Sapphire Rapids, Bergamo)

        To map the M2, the base is about the same as most x86 consumer grade, the Pro is about Threadripper, and the ultra is somewhere between single or dual socket Bergamo, at least in terms of memory bandwidth, which is a highly specific metric.

        • @[email protected]English
          3•1 year ago

          Oh gotcha, thanks for straightening me out on that. I’m still learning tech so the examples are really helpful