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

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

In article .com,
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/

In article .com,
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/

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).

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
oups.com...
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

Alfred Molon wrote:
In article .com,
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

Alfred Molon wrote:
In article .com,
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

In article . com,
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.

In article . com,
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 wrote:
In article . com,
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.

--=20
Barry Pearson=20
www.barry.pearson.name/photogr=ADaphy