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SD Association Unveils microSD Express Format That Promises Transfer Speeds of Up To 985 MB/s (engadget.com)

Posted by msmash on from the how-about-that dept.

The SD Association has unveiled microSD Express, a new format that will bring speeds of up to 985 MB/s to the tiny memory cards used in smartphones and other devices. From a report: Like SD Express, it exploits the NVMe 1.3 and PCIe 3.1 interfaces used in PCs to power high-speed SSDs. The tech is incorporated onto the second row of microSD pins, so the cards will work faster in next-gen devices while maintaining backward compatibility with current microSD tech. PCIe 3.1 allows for low power sub-states, so the cards will not only offer much (much) higher transfer speeds, but consume less power than regular microSD cards. It'll also open up features like bus mastering, which lets memory cards communicate with other components without going through the CPU first.

8 of 72 comments (clear)

  1. Countdown to... by WoodstockJeff · · Score: 4, Insightful

    ... bus mastering being used in an Intel processor exploit in 10, 9, 8 ...

    1. Re:Countdown to... by DarkOx · · Score: 4, Insightful

      This was my first thought as well. It seems to me extending to the PCIe bus to all kinds of untrusted hot plugged devices has bad idea written all over it. USB 2.x we "permissive" enough in terms of memory access.

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    2. Re:Countdown to... by tlhIngan · · Score: 3, Interesting

      This was my first thought as well. It seems to me extending to the PCIe bus to all kinds of untrusted hot plugged devices has bad idea written all over it.

      We already did, twice. First was ExpressCard, which is a card version of a x1 PCIe slot. Second time was Thunderbolt, which I believe the current iteration is up to x4 PCIe.

      And yes, I believe there are Thunderbolt RAM attacks though because of the IO controller, it's somewhat mitigated.

  2. MB/s not Mb/s by Vairon · · Score: 5, Informative

    microSD Express format supports up to 985 MB/s not 985 Mb/s.

    MB/s is megabytes (1,000,000 bytes) per second.
    Mb/s is megabits (1,000,000 bits) per second.

    References:
    https://www.sdcard.org/press/T...

  3. limits by blackomegax · · Score: 4, Interesting

    NAND is limited by how many chips are stacked behind the controller. microSD is limited to a single chip. This is why, even with current 90MB/s rated microsd, you still get 7MB/s speeds from it once you fill up the controller buffer. NVMe on a single chip shitNAND? lol. this is pure marketing bullshit.

    1. Re:limits by williamyf · · Score: 4, Interesting

      Until they begin making (micro)SD cards out of 3DxPoint, ReRam, Phase Changing RAM or Mermistors...

      You see, the (micro)SD format is not tied to Flash, therefore, the need to future-proof the bus...

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    2. Re:limits by thegarbz · · Score: 3, Informative

      Ignore the OP. He's buying cheap Chinese shit. Most reputable cards will happily max out the SD card's current bus for a sustained write across their entire capacity and despite his assertion that NAND is the limiting factor to 7MB/s you'll find most SSDs have either 2 or 4 NAND chips on them and happily crank out several gigabytes per second of data.

  4. Re:Larger cards by Vairon · · Score: 3, Informative

    The speed is actually 985 MB/s not 985 Mb/s. The article was wrong. See https://www.sdcard.org/press/T...