Earlier quoted context omitted.
> LPCAMM2 supports up to 9600MT/s, which appears to be the same speed Apple is using. The difference here is in what the standard defines on paper vs what is actually shipping in products and readily available off the shelf. Who's selling a whole system with LPCAMM2 certified for 9600MT/s? Intel's current-gen Panther Lake top of the line laptop chips are rated for 9600MT/s when using soldered LPDDR5x but only 7467MT/…
> Who's selling a whole system with LPCAMM2 certified for 9600MT/s? The 9600MT/s modules are new and will probably be found at some point this year. Framework already sells LPCAMM2 at 8533MT/s with full validation: https://knowledgebase.frame.work/what-drammemory-is-supporte... > That puts the current Intel-with-LPCAMM2 supported memory speed at 1.5 years and counting lag behind Apple's shipping memory speeds. It tur…
From your link:
> Framework Laptop 13 Pro (Intel® Core™ Ultra Series 3) supports one slot of LPCAMM2 memory up to 96GB at the native 7467 MT/s speed. It is compatible with LPCAMM2 modules with memory speed rated above 7467 MT/s, but the speed will be capped at 7467 MT/s because of the platform limitation.
The modules in question can only theoretically operate at 8533MT/s. Framework has yet to sell a system where the modules actually operate at more than 7467MT/s.
> It turns out Apple isn't getting 9600MT/s either. I assumed that soldering would be getting them at least what LPCAMM2 is rated for, but if you actually do the math, they're getting ~8500MT/s for their most expensive systems and ~7500MT/s for the others.
You're either doing the math wrong, or just plain looking at the wrong systems. Try looking at the M5 generation.
> CAMM modules use a compression fitting to attach the chips to the system board using approximately the same amount of space as the solder pads would for soldered chips. If you get to the point of having so many channels that the chips are in the way of the other chips then the soldered ones have the same problem.
Yes, that's a problem, and Apple has solved it by moving the DRAM on-package. Datacenter GPUs have also solved it that way by putting the DRAM on a silicon interposer to allow even wider bus widths. Soldering standard DRAM packages on the motherboard is not the limit of how memory can be soldered down.
> A single LPCAMM2 module is a 128-bit bus. Every system that uses it has at least that.
Yes, 128 bits at lower speeds. Did you forget that the whole point I'm making here is that the speeds are not the same?
> Nobody is really using a bus that wide with soldered memory either though, outside of the couple of Macs that start at ~$3500 and are getting the same speed Framework does with LPCAMM2.
The Mac Studio with the M3 Ultra is actually running the DRAM at a lower frequency than what Framework and other Intel-based systems could, but more than making up for it in bus width, to provide far more total memory bandwidth than any plausible LPCAMM2-based system that could be built today.