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> The PCIe interfaces SSDs that Apple's been using allow really fast speeds of upto 3Gbps AnandTech reported int heir review of the 2015 Macbook that this was

> The PCIe interfaces SSDs that Apple's been using allow really fast speeds of upto 3Gbps AnandTech reported int heir review of the 2015 Macbook that this was just NVMe. Has something changed since then? This is just Apple again trying to pass off a standard as their own innovation to justify their proprietary incarnation.

mrpippy 8y ago
It's NVMe to the T2 SoC, which acts as the storage controller (among many other tasks). It would be nice to have the raw NAND on a removable card, but the market for "raw-NAND-on-a-stick" would be entirely limited to these machines.
- luka-birsa 8y ago
  Come on guys, they are just ripping us off. There is no sane reason for removing m2 connector. SSDs can run pcie over m2 and there is no way they run something custom there. Its bullshit marketing that enables them to sell you overpriced ssd and mem upgrades or make you replace your PC faster.
  - derefr 8y ago
    It's not that they couldn't make m.2 PCIe NAND; it's that nobody else is making m.2 PCIe NAND. The T2's storage controller wouldn't know what to do with any other (NVMe or SATA) m.2 SSD, since then it'd be the T2's storage controller talking to the SSD's storage controller.
    - kllrnohj 8y ago
      That's incredibly false. Literally everyone makes m.2 PCIe NAND. In fact it's increasingly hard to find M.2 SATA these days with how overwhelmingly common PCI-E 3.0 x4 M.2 is. And M.2 PCI-E isn't just stupid common, it's also cheap. Really, really cheap. 1TB of crazy fast PCI-E nand is $230: https://www.amazon.com/Samsung-970-EVO-1TB-MZ-V7E1T0BW/dp/B07BN217QG/ref=sr_1_2?s=pc&ie=UTF8&qid=1541813007&sr=1-2&keywords=970+Evo https://www.amazon.com/Samsung-970-EVO-1TB-MZ-V7E1T0BW/dp/B0...
      - derefr 8y ago
        Er, no, you didn't understand my statement at all. What you're talking about is NVMe NAND—which is a standard protocol on top of PCIe. If you aren't aware, both the PCIe m.2 NVMe SSDs, and the PCIe "card" NVMe SSDs, and even the DIMM-slot SDRAM-speaking NVMe SSDs, all still contain a flash controller behind their PCIe/SDRAM controller, which implements the standard NVMe protocol, acting as a translator between the host's decoded commands from the bus, and the NAND's proprietary protocol. And, like all other flash controllers, the flash controllers in NVMe SSDs do a host of "enrichments" to the abstraction they expose, like opaque wear-levelling. Whereas what I'm talking about—"direct PCI-e NAND"—refers to the concept of NAND memory sitting directly on the PCIe bus with no flash controller, just a PCIe controller. This would, if it existed, allow the host to directly program and erase NAND blocks—as if the host was the flash controller—by sending the NAND commands in the NAND's own proprietary command format, wrapped into PCIe packets. Directly-addressable NAND has none of the "enrichment" a flash-controller provides to NVMe NAND, and directly-addressable NAND also speaks whatever dumb protocol the NAND's manufacturer makes it speak, requiring a special custom driver per NAND (or a host-side flash controller.) Old embedded systems (like phones and cameras ca. 2002) used to contain directly-addressable NAND, soldered onto the motherboard. They mostly switched away from this to using eMMC chips—those being single BGA packages containing a flash controller and NAND—because they were gaining no advantage from having a separate flash controller, only inconveniences (like having to write their own storage drivers) and/or costs (of adding their own flash controller to the embedded board's BOM.) Old iOS devices used to use eMMC. But, since the creation of the Secure Enclave, Apple has found an advantage to having a discrete flash controller: namely, that it can interact with the Secure Enclave. So, since the iPhone 6, Apple stopped using eMMC in favor of their own flash controller + directly-soldered NAND flash. And now, Apple have done the same thing to the Mac Mini that they did to iOS devices: switched from an interface that expects to find a flash controller speaking a standard protocol (NVMe or SATA), to an interface where the flash controller is on the host side and expects to find directly-addressable NAND flash on the other side for it to manage. Attaching an m.2 NVMe SSD to that interface, would be similar in effect to what you'd get by taking one of those old phones that uses directly-soldered NAND with a host-side flash controller, and instead of soldering in NAND, soldering an eMMC card in its place. In short: you'd have a dead device.

mrpippy 8y ago

It's NVMe to the T2 SoC, which acts as the storage controller (among many other tasks). It would be nice to have the raw NAND on a removable card, but the market for "raw-NAND-on-a-stick" would be entirely limited to these machines.

luka-birsa 8y ago
Come on guys, they are just ripping us off. There is no sane reason for removing m2 connector. SSDs can run pcie over m2 and there is no way they run something custom there. Its bullshit marketing that enables them to sell you overpriced ssd and mem upgrades or make you replace your PC faster.
- derefr 8y ago
  It's not that they couldn't make m.2 PCIe NAND; it's that nobody else is making m.2 PCIe NAND. The T2's storage controller wouldn't know what to do with any other (NVMe or SATA) m.2 SSD, since then it'd be the T2's storage controller talking to the SSD's storage controller.
  - kllrnohj 8y ago
    That's incredibly false. Literally everyone makes m.2 PCIe NAND. In fact it's increasingly hard to find M.2 SATA these days with how overwhelmingly common PCI-E 3.0 x4 M.2 is. And M.2 PCI-E isn't just stupid common, it's also cheap. Really, really cheap. 1TB of crazy fast PCI-E nand is $230: https://www.amazon.com/Samsung-970-EVO-1TB-MZ-V7E1T0BW/dp/B07BN217QG/ref=sr_1_2?s=pc&ie=UTF8&qid=1541813007&sr=1-2&keywords=970+Evo https://www.amazon.com/Samsung-970-EVO-1TB-MZ-V7E1T0BW/dp/B0...
    - derefr 8y ago
      Er, no, you didn't understand my statement at all. What you're talking about is NVMe NAND—which is a standard protocol on top of PCIe. If you aren't aware, both the PCIe m.2 NVMe SSDs, and the PCIe "card" NVMe SSDs, and even the DIMM-slot SDRAM-speaking NVMe SSDs, all still contain a flash controller behind their PCIe/SDRAM controller, which implements the standard NVMe protocol, acting as a translator between the host's decoded commands from the bus, and the NAND's proprietary protocol. And, like all other flash controllers, the flash controllers in NVMe SSDs do a host of "enrichments" to the abstraction they expose, like opaque wear-levelling. Whereas what I'm talking about—"direct PCI-e NAND"—refers to the concept of NAND memory sitting directly on the PCIe bus with no flash controller, just a PCIe controller. This would, if it existed, allow the host to directly program and erase NAND blocks—as if the host was the flash controller—by sending the NAND commands in the NAND's own proprietary command format, wrapped into PCIe packets. Directly-addressable NAND has none of the "enrichment" a flash-controller provides to NVMe NAND, and directly-addressable NAND also speaks whatever dumb protocol the NAND's manufacturer makes it speak, requiring a special custom driver per NAND (or a host-side flash controller.) Old embedded systems (like phones and cameras ca. 2002) used to contain directly-addressable NAND, soldered onto the motherboard. They mostly switched away from this to using eMMC chips—those being single BGA packages containing a flash controller and NAND—because they were gaining no advantage from having a separate flash controller, only inconveniences (like having to write their own storage drivers) and/or costs (of adding their own flash controller to the embedded board's BOM.) Old iOS devices used to use eMMC. But, since the creation of the Secure Enclave, Apple has found an advantage to having a discrete flash controller: namely, that it can interact with the Secure Enclave. So, since the iPhone 6, Apple stopped using eMMC in favor of their own flash controller + directly-soldered NAND flash. And now, Apple have done the same thing to the Mac Mini that they did to iOS devices: switched from an interface that expects to find a flash controller speaking a standard protocol (NVMe or SATA), to an interface where the flash controller is on the host side and expects to find directly-addressable NAND flash on the other side for it to manage. Attaching an m.2 NVMe SSD to that interface, would be similar in effect to what you'd get by taking one of those old phones that uses directly-soldered NAND with a host-side flash controller, and instead of soldering in NAND, soldering an eMMC card in its place. In short: you'd have a dead device.