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Re: Flash Drive vs. CF Adapter

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  • Mitch Wolfson
    Thanks for the good explanation, Dave Point 3 is probably the most significant one, since a CF card is dumb in this respect. Of course, designing my own
    Message 1 of 4 , Sep 7, 2006
      Thanks for the good explanation, Dave

      Point 3 is probably the most significant one, since a CF card
      is "dumb" in this respect. Of course, designing my own system means
      I use the "generic" IRLP install O/S, so the CF card would be
      written quite often. Supposedly cards are now good for several 100k
      writes per sector, but nevertheless this ia an issue with flash in
      general.

      What does the flash drive cost, and what is the capacity? The CF
      adapter with 2GB costs about 60 euros, and the only flash drives I
      have seen till now cost more than double that with less memory.

      73,
      Mitch DJØQN/K7DX

      --- In irlp-embedded@yahoogroups.com, David Cameron - IRLP
      <dcameron@...> wrote:
      >
      > Three reasons:
      >
      > 1) The CF card adapter requires room. Size is a premium in these
      cases.
      >
      > 2) The combination of a CF card and the adapter is actually
      slightly more
      > expensive than the IDE flash drive.
      >
      > 3) The filesystem of the IDE flash drive is actually "wear
      sharing", in
      > that the same areas of the drive are not always used for
      read/write.
      >
      > The software is done in such a way that the filesystem is run from
      RAM,
      > and does not write to the card.
      >
      > A CF adapter will work fine as well.
      >
      > Dave Cameron
      > VE7LTD
      >
      > On
      > Thu, 7 Sep 2006, Mitch Wolfson wrote:
      >
      > > Dave,
      > >
      > > I was just curious why you chose the more expensive Flash Drive
      > > solution instead of a CF card with IDE adapter (which costs
      12.90 euro
      > > here). I would not think that performance would be the reason, so
      > > maybe reliability or something else?
      > >
      > > I built my fanless mini-ITX system shortly before you announced
      yours,
      > > but put in a 2.5" HD to allow me to possibly run more server
      apps in
      > > the future. I thought about using the CF adapter with a 2GB CF
      card at
      > > the time.
      > >
      > > 73,
      > > Mitch DJØQN/K7DX
      > >
      > > IRLP node 5378
      > >
      > >
      > >
      > >
      > >
      > >
      > >
      > > Yahoo! Groups Links
      > >
      > >
      > >
      > >
      > >
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      > >
      > >
      > >
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    • David Cameron - IRLP
      The cost is about $40US for 128 megs... Here the CF-IDE adapter costs $20, and you can not buy a 128M CF for $20... For larger sizes, yes, CF is the way to go,
      Message 2 of 4 , Sep 7, 2006
        The cost is about $40US for 128 megs... Here the CF-IDE adapter costs
        $20, and you can not buy a 128M CF for $20... For larger sizes, yes, CF
        is the way to go, price wise only.

        I am thinking of selling an OS loaded IDE-flash for $100 US. It did take
        me 4 months of 3-4 hours a night to build it :) This will work in any
        mini-ITX machine that uses the VT1616 audio chipset.

        The embedded IRLP OS is only 34 megs with IRLP and Echolink installed.
        That size will come down a bit once I am able to get the audio files to be
        streamed across the connection.

        This loads into 256 megs of ram, as a 120 meg flash drive (so you can not
        exceed the amount of the drive when you mirror it back), and then with 16
        megs shared for video (as small as it goes), the OS just flies in the
        remaining RAM. There is NO RAM DRIVE, which is important to note, as if
        you use a RAM drive on a CF, your 100K writes will be dead, or really
        crippled, in less than 6 months.

        The way these embedded nodes run, I estimate a MTBF (mean time between
        failures) of something like 100000 hours, at which time the mobo or RAM
        will need to be replaced as well (12 years or so). I have similar Redhat
        6.2 based embedded machines that have not had a hiccup in 5 years.

        Dave Cameron
        VE7LTD



        On Thu, 7
        Sep 2006, Mitch Wolfson wrote:

        > Thanks for the good explanation, Dave
        >
        > Point 3 is probably the most significant one, since a CF card
        > is "dumb" in this respect. Of course, designing my own system means
        > I use the "generic" IRLP install O/S, so the CF card would be
        > written quite often. Supposedly cards are now good for several 100k
        > writes per sector, but nevertheless this ia an issue with flash in
        > general.
        >
        > What does the flash drive cost, and what is the capacity? The CF
        > adapter with 2GB costs about 60 euros, and the only flash drives I
        > have seen till now cost more than double that with less memory.
        >
        > 73,
        > Mitch DJØQN/K7DX
        >
        > --- In irlp-embedded@yahoogroups.com, David Cameron - IRLP
        > <dcameron@...> wrote:
        >>
        >> Three reasons:
        >>
        >> 1) The CF card adapter requires room. Size is a premium in these
        > cases.
        >>
        >> 2) The combination of a CF card and the adapter is actually
        > slightly more
        >> expensive than the IDE flash drive.
        >>
        >> 3) The filesystem of the IDE flash drive is actually "wear
        > sharing", in
        >> that the same areas of the drive are not always used for
        > read/write.
        >>
        >> The software is done in such a way that the filesystem is run from
        > RAM,
        >> and does not write to the card.
        >>
        >> A CF adapter will work fine as well.
        >>
        >> Dave Cameron
        >> VE7LTD
        >>
        >> On
        >> Thu, 7 Sep 2006, Mitch Wolfson wrote:
        >>
        >>> Dave,
        >>>
        >>> I was just curious why you chose the more expensive Flash Drive
        >>> solution instead of a CF card with IDE adapter (which costs
        > 12.90 euro
        >>> here). I would not think that performance would be the reason, so
        >>> maybe reliability or something else?
        >>>
        >>> I built my fanless mini-ITX system shortly before you announced
        > yours,
        >>> but put in a 2.5" HD to allow me to possibly run more server
        > apps in
        >>> the future. I thought about using the CF adapter with a 2GB CF
        > card at
        >>> the time.
        >>>
        >>> 73,
        >>> Mitch DJØQN/K7DX
        >>>
        >>> IRLP node 5378
        >>>
        >>>
        >>>
        >>>
        >>>
        >>>
        >>>
        >>> Yahoo! Groups Links
        >>>
        >>>
        >>>
        >>>
        >>>
        >>>
        >>>
        >>>
        >>>
        >>>
        >>>
        >>>
        >>
        >
        >
        >
        >
        >
        >
        >
        >
        >
        > Yahoo! Groups Links
        >
        >
        >
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        >
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