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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.

14 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.

      --
      Repeal the 17th Amendment TODAY! Also Please Read http://www.gnu.org/philosophy/right-to-read.html
    2. Re:Countdown to... by gweihir · · Score: 2

      Well, those that prefer speed over security will at least not have security. The funny thing is that these morons are the ones to complain loudest when they get hit because of their own stupidity...

      --
      Most ACs are not even worth the keystrokes to insult them. Be generically insulted by this and ignored otherwise.
    3. 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...

      --
      *** Suerte a todos y Feliz dia!
    2. Re:limits by wierd_w · · Score: 2

      There are some cards with more than a single flash chip inside them, but they are always full size sdcards.

      Here's an example.

      https://upload.wikimedia.org/w...

      Most will only be a single chip though.

      The big bottleneck is the controller itself, which manipulates the flash. SDCard uses a serial protocol, not a parallel data IO direct to the flash chip. The flash chip could be hella fast, but if there is a cheap and slow controller driving it.. That's like putting an SSD on a SATA I interface.

    3. 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...

  5. 985MB/s Sustainable Into or Out of the Card? by mykepredko · · Score: 2

    When you see "985MB/s transfer speeds", I suspect that you're assuming that the card can read and write data at this speed all day long.

    But, I suspect that there are limits in terms of writing and accessing data. I'm sure burst speeds of 985MB/s is possible (with longer read bursts than write) but the overall/average speed will probably be 20-50MB/s, which is still very good, but not what you're being lead to believe.

    --
    Mimetics Inc. Twitter
    1. Re:985MB/s Sustainable Into or Out of the Card? by DigiShaman · · Score: 2

      Depends on the lithography process, but my Samsung 950 Pro will eventually get heat-soaked and throttled if slinging sustained R/Ws long enough. Casual use and bust access won't be an issue.

      Basically, the small cards have such as small thermal mass that you won't be using them to record slow-mo video in 4k anytime soon - they're overheat!

      --
      Life is not for the lazy.
    2. Re:985MB/s Sustainable Into or Out of the Card? by thegarbz · · Score: 2

      Interestingly the heat throttling of modern NVMe SSDs has nothing to do with the memory and everything to do with the controller. I would highly recommend a heatsink, and when you get the heatsink you want to apply the pad so it touches only the controller. NAND works better when it's hot which is why it has a minimum temperature rating.

  6. Re:Just why is 10 Gbps still so expensive? by LostMyAccount · · Score: 2

    The big problem with 10gbps is that it's too fast to handle with more than a few feet of copper, and fiber is a BITCH to terminate.

    Maybe its misinformation? The spec lists it at 100 meters over Cat-6a and 50 meters over Cat-6. I've had zero problems with it using Cat-6 at ordinary data center lengths up to about 10 meters.

    It's advantage in many environments isn't just the added speed -- it adds a ton of performance for even rotational media SAN, but the fact that its running on a 10x faster clock, cutting latency times as well, even for applications which aren't exceeding 1 Gbit throughput limitations. As for too slow, well, you can already run 1080p HDMI over Cat 6 and any other "video" you may want to run over network cable distances would be best handled as an ordinary network video stream using existing streaming media encoding. Anything else needing more speed already has datacenter speeds 25/40/100Gps over twinax or fiber.

    Its marginally overkill at the desktop, but 10GBase-T has the advantage of being 10x faster, cheaper, simpler cabling than fiber or twinax, and backwards compatible with 1 Gbps.