Memory Card RAID

Discussion in 'Community Discussion' started by guzhogi, Jul 8, 2009.

  1. guzhogi macrumors 68030


    Aug 31, 2003
    Wherever my feet take me…
    I was just thinking, it would be interesting to see someone make a RAID device of memory cards (like Secure Digital or Compact Flash or something). Just to see what kind of speed you can get. It'd be a REALLY small RAID, but who cares? It would also be cool if someone made like a 1U rack mount (or any U rack mount) and put space for however many SD cards can fit. I'm sure I'm not the 1st to think of something like this.
  2. dmr727 macrumors G3


    Dec 29, 2007
  3. uberamd macrumors 68030


    May 26, 2009
    Wouldn't that be a lot slower than a standard hard drive? I guess I don't know much about it but USB 2.0 has a 480Mbps transfer speed. Thus if you hooked a SD-card RAID up to a system via USB, it would be significantly slower than the 3072Mbps speed that a SATA controller sports.
  4. balofagus macrumors regular

    Jan 11, 2006
    Ontario, Canada
    Does this count? P2 Memory Card

    I don't really know anything else about them. My old roommate has one for his Panasonic HVX...
  5. Signal-11 macrumors 65816


    Mar 23, 2008
    2nd Star to the Right
    :eek: Wow, there's always some dude on teh internets who's thought of it, done it, and posted the instructions.
  6. FX120 macrumors 65816


    May 18, 2007
    In terms of raw data thoroughput, most flash cards don't match the newest high-capacity, high RPM magnetic disks. Access time is much faster, yes, but that isn't something that is improved in a RAID array. Even the fastest "300x" UMDA CF cards top out at about 45MB/sec write, which isn't all that great.

    By comparison my 750GB 7200.11's do about 110MB/sec - 70MB/sec write, and my current array averages about 200MB/sec (6 drives, RAID 0+1).

    And that is with inexpensive consumer level 7200RPM drives. Step up to high-density SAS 15kRPM drives, and you're looking at data transfer rates as high as 200MB/sec write, and that's with a single drive.

    If you're really insane, there are PCIe "ram drives", which use DDR2 DIMM's, and are basically limited only by the bus itself, and offer lightning quick access times, actually they're pretty much non-existant. The downside is that the RAM has to be kept powered, or else any data stored will be lost.

    Unless you're going for something silent, or really need the access times, you're probably better of spending your money on large magnetic drives, which will not only be larger in capacity, but probably cheaper by the time you buy all the UMDA readers to go along with the cards.

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