The Universe of Managed NAND

Posted by: Thom Denholm

We have talked about managed NAND in a few blog posts before. Usually a combination of raw NAND flash (SLC or MLC) combined with a hardware controller that performs flash management features like bad block management, ECC and wear leveling is referred to as managed NAND. The term covers a huge spectrum of flash-based storage devices so in this post we will try and highlight some of the more prevalent types of managed NAND The following is an enumeration of some of the popular managed NAND form factors. Please note that the list covers flash technologies used for resident storage and does not cover removable storage like USB flash, SD, etc.

 

  • eMMC
  • eSD
  • CompactFlash
  • Solid State Drives
  • BA NAND
  • Adaptable NAND
  • Specialized  

 

Specially designed controller + raw flash CompactFlash is included here because it is used both as resident and removable storage. CF comes with a Fixed-drive option which allows it to be used a resident managed NAND. The above technologies differ from each other on several attributes

  • Form factor - managed NAND can come is several form factors. An SSD may sport a standard 2.5" drive enclosure whereas a CF card will take a 1.0" card form factor. • Plug-in interface: What interface does the managed NAND use to connect to the device platform -    MMC -    SD -    ATA -    Custom
  • Cost: Cost depends on several elements 

Type of flash used: SLC is much more expensive than MLC - Type of controller used: consumer grade controllers (used for consumer grade CF for example) are much cheaper than specialized industrial grade controllers

  • Performance -    Performance varies depending on the flash type, the controller attributes and the interface. Some of the big players in the managed NAND business are
  • eMMC -    Micron, Numonyx
  • eSD -    SanDisk, Toshiba •    BA NAND -    Toshiba
  • Solid State Drives, CompactFlash    

Too many players in these markets This was a brief view of the managed NAND landscape. If there is interest, we will do a follow up going in details about the specific categories and interfaces


Comments (5)

  1. Barun:
    Jun 15, 2010 at 11:10 AM

    "Form factor - managed NAND can come is several form factors. An SSD may sport a standard 2.5" drive enclosure whereas a CF card will take a 1.0" card form factor." Can you tell us of some of the CF devices, which has a managed NAND or moviNAND inside?

  2. Amid:
    Jul 22, 2009 at 10:43 AM

    Hello, I do enjoy the blog postings on your website. They are very informative and interesting to read. Thank you

  3. Walter Rivera:
    Jul 09, 2009 at 09:02 AM

    Can you do a comparison of the advantages of unmanaged NAND versus Managed NAND? What are the cost tradeoffs, density tradeoffs, and other limitations of each?

  4. Mayur Kamat:
    Jul 10, 2009 at 10:36 AM

    We published something on that regard a few months back. Here is the link http://blog.datalight.com/why-raw-nand-flash-with-hardware-based-ecc-is-the-way-to-go

  5. Wenyu:
    Nov 16, 2012 at 03:13 AM

    In a related blog "The Datalight Labs: Managed NAND vs. Raw NAND" (link below), the author mentioned some Digi test board. May I ask the exact model and where can I buy it? Thanks! http://blog.datalight.com/tag/managed-nand#ixzz2CNdCUmoB


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