Pentax *istD can't exploit fast cards such as Lexar WA cards

Discussion in 'Digital Photography' started by Barry Pearson, Apr 13, 2005.

  1. I raised this subject in a thread "Pentax *istD & Lexar WA technology -
    any experience?". (No responses!) I wondered why my Pentax was only
    writing to a Lexar 80x WA card at 2MB per second, although the card
    supports 12MB per second even without Write Acceleration technology,
    and should be up to 23% faster with WA technology.

    I have had a long on-line dialogue with Lexar support, and a
    substantial telephone conversation with a Lexar technician. The
    conclusion appears to be that the Pentax *istD is incapable of writing
    to ANY card much better than 2MB per second, whatever the speed of the
    card or the acceleration technology supposedly used.

    This suggests that if you want faster write speed than 2MB per second,
    don't buy a Pentax *istD. And if you have a Pentax *istD, you may see
    no performance advantage from a card that is significantly faster than
    2MB per second. The bottleneck appears to be in the Pentax, not in the
    card. And that applies to Sandisk Ultra II cards too.

    In the Lexar labs, their bus analyser shows that the Pentax does indeed
    use the WA standard. But it takes 5.7 seconds to transfer 14MB, even
    without the extra overheads that the Pentax needs to store a Raw file.
    Lexar's tests of the Pentax writing to a Sandisk Ultra II card was 6
    seconds, very little difference. The 7 seconds I was seeing for a 13MB
    file included overheads that their bus analyser wasn't looking at. All
    these figures are probably reasonably consistent.

    Lexar promote the fact that the Pentax *istD supports WA technology.
    But the slowest Lexar card with WA technology is far faster than the
    Pentax can handle even WITHOUT WA technology! It may be that WA
    technology in the Pentax *istD is totally irrelevant, used for mutual
    Pentax/Lexar promotion, not for photographer benefit.

    --
    Barry Pearson
    www.barry.pearson.name/photography
     
    Barry Pearson, Apr 13, 2005
    #1
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  2. Barry Pearson

    Alfred Molon Guest

    In article <>,
    Barry Pearson says...
    > I raised this subject in a thread "Pentax *istD & Lexar WA technology -
    > any experience?". (No responses!) I wondered why my Pentax was only
    > writing to a Lexar 80x WA card at 2MB per second, although the card
    > supports 12MB per second even without Write Acceleration technology,
    > and should be up to 23% faster with WA technology.


    Most digital cameras including DSLRs can't keep up with the fastest
    memory cards. Even DLRs seem to top out at about 5-6MB/s, with the
    exception of the E300 which reaches 9MB/s sustained.
    --

    Alfred Molon
    ------------------------------
    Olympus 4040, 5050, 5060, 7070, 8080, E300 forum at
    http://groups.yahoo.com/group/MyOlympus/
    Olympus E300 resource - http://myolympus.org/E300/
     
    Alfred Molon, Apr 13, 2005
    #2
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  3. Barry Pearson

    Bill Hilton Guest

    > Barry Pearson writes ...
    >
    >I wondered why my Pentax was only writing to a Lexar 80x WA
    >card at 2MB per second, although the card supports 12MB per
    >second


    This sounds about right, the Canon 10D only does about 1.4 MB/sec with
    that card, the Canon 20D about 5.7 MB/sec (from Galbraith's tests).
     
    Bill Hilton, Apr 13, 2005
    #3
  4. Barry Pearson

    Tony Guest

    It is like CD-Rs. The speed is determined by the divice that writes, until
    you each the maximum writable speed of the media. I buy CD-Rs that are
    capable of being written by my fastestburner, which is somewhere around 40x,
    but use the same CDs in my older 24x and 8x writers too.

    --
    http://www.chapelhillnoir.com
    home of The Camera-ist's Manifesto
    The Improved Links Pages are at
    http://www.chapelhillnoir.com/links/mlinks00.html
    A sample chapter from "Haight-Ashbury" is at
    http://www.chapelhillnoir.com/writ/hait/hatitl.html

    "Barry Pearson" <> wrote in message
    news:...
    > I raised this subject in a thread "Pentax *istD & Lexar WA technology -
    > any experience?". (No responses!) I wondered why my Pentax was only
    > writing to a Lexar 80x WA card at 2MB per second, although the card
    > supports 12MB per second even without Write Acceleration technology,
    > and should be up to 23% faster with WA technology.
    >
    > I have had a long on-line dialogue with Lexar support, and a
    > substantial telephone conversation with a Lexar technician. The
    > conclusion appears to be that the Pentax *istD is incapable of writing
    > to ANY card much better than 2MB per second, whatever the speed of the
    > card or the acceleration technology supposedly used.
    >
    > This suggests that if you want faster write speed than 2MB per second,
    > don't buy a Pentax *istD. And if you have a Pentax *istD, you may see
    > no performance advantage from a card that is significantly faster than
    > 2MB per second. The bottleneck appears to be in the Pentax, not in the
    > card. And that applies to Sandisk Ultra II cards too.
    >
    > In the Lexar labs, their bus analyser shows that the Pentax does indeed
    > use the WA standard. But it takes 5.7 seconds to transfer 14MB, even
    > without the extra overheads that the Pentax needs to store a Raw file.
    > Lexar's tests of the Pentax writing to a Sandisk Ultra II card was 6
    > seconds, very little difference. The 7 seconds I was seeing for a 13MB
    > file included overheads that their bus analyser wasn't looking at. All
    > these figures are probably reasonably consistent.
    >
    > Lexar promote the fact that the Pentax *istD supports WA technology.
    > But the slowest Lexar card with WA technology is far faster than the
    > Pentax can handle even WITHOUT WA technology! It may be that WA
    > technology in the Pentax *istD is totally irrelevant, used for mutual
    > Pentax/Lexar promotion, not for photographer benefit.
    >
    > --
    > Barry Pearson
    > www.barry.pearson.name/photography
    >
     
    Tony, Apr 14, 2005
    #4
  5. Alfred Molon wrote:
    > In article <>,
    > Barry Pearson says...
    > > I raised this subject in a thread "Pentax *istD & Lexar WA

    technology -
    > > any experience?". (No responses!) I wondered why my Pentax was only
    > > writing to a Lexar 80x WA card at 2MB per second, although the card
    > > supports 12MB per second even without Write Acceleration

    technology,
    > > and should be up to 23% faster with WA technology.

    >
    > Most digital cameras including DSLRs can't keep up with the fastest
    > memory cards. Even DLRs seem to top out at about 5-6MB/s, with the
    > exception of the E300 which reaches 9MB/s sustained.


    The Pentax *istD is a digital SLR, with Write Acceleration technology.
    I wish it could reach 5-6MB/s! I suspect that it will never exceed
    2MB/sec whatever the card.

    I bought it because of my investment in lenses & flashguns, etc.
    Perhaps I should have accepted the cost of replacing the whole lot
    (probably with Canon). It is a competent camera, (and light), but
    Pentax have lost their way, and I would only recommend it to anyone
    else with a major investment in Pentax lenses.

    --
    Barry Pearson
    www.barry.pearson.name/photography
     
    Barry Pearson, Apr 14, 2005
    #5
  6. Barry Pearson

    Chris Brown Guest

    In article <>,
    Bill Hilton <> wrote:
    >> Barry Pearson writes ...
    >>
    >>I wondered why my Pentax was only writing to a Lexar 80x WA
    >>card at 2MB per second, although the card supports 12MB per
    >>second

    >
    >This sounds about right, the Canon 10D only does about 1.4 MB/sec with
    >that card, the Canon 20D about 5.7 MB/sec (from Galbraith's tests).


    This seems to be a really big issue for some people. One can't help but
    think that if they wanted to shoot continuous video, they'd be better off
    with a video camera. That way, they get to record their continuous stream of
    pictures, and don't have to put up with the mirror flapping about between
    frames.
     
    Chris Brown, Apr 14, 2005
    #6
  7. Chris Brown wrote:
    > In article <>,
    > Bill Hilton <> wrote:
    > >> Barry Pearson writes ...
    > >>
    > >>I wondered why my Pentax was only writing to a Lexar 80x WA
    > >>card at 2MB per second, although the card supports 12MB per
    > >>second

    > >
    > >This sounds about right, the Canon 10D only does about 1.4 MB/sec

    with
    > >that card, the Canon 20D about 5.7 MB/sec (from Galbraith's tests).

    >
    > This seems to be a really big issue for some people. One can't help

    but
    > think that if they wanted to shoot continuous video, they'd be better

    off
    > with a video camera. That way, they get to record their continuous

    stream of
    > pictures, and don't have to put up with the mirror flapping about

    between
    > frames.


    I was talking about shooting Raw photographs, not video. The Pentax
    *istD appears to be limited to taking about 13 Raw photographs within
    the first 60 seconds of switching it on, even with the fastest cards.
    Or one Raw photograph every 7 seconds if sustained over minutes. That
    is quite slow when shooting people or animals in motion.

    --
    Barry Pearson
    www.barry.pearson.name/photogr­aphy
     
    Barry Pearson, Apr 14, 2005
    #7
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