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02-26-2010, 07:57 AM   #1
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K-x - data speed records on SD card

In a month I will become a new owner of K-x, but nowhere on the net can not find the fact of K-x speed records images on SD card. Same for HD video. I am interested to know that so I can buy apropriate SD card - Class6 or faster(?) 32GB class6 is quite expensive, so if there is no need to be faster it will be great!

02-26-2010, 09:07 AM   #2
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my k-x came with a Kingston 4GB Class 4. Not the fastest card around I believe, but it can record HD *** video until the batteries over-heat (about 8-10 minutes).

I'm also wondering if 4GB Class6 is faster than 8GB Class6 is faster than 16GB Class6... ?
02-26-2010, 10:20 AM   #3
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I bought a 16 Gig Class 6 adata card from newegg a few weeks ago for $30. Was a good price at the time.

I was able to take 15 shots, just holding down the shutter button in the higher res setting without any delay at all.

I didnt try it with the class 2 PNY cards that came with the camera.
02-26-2010, 10:38 AM   #4
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Class info can be very misleading. As Class 6 is the fastest fully approved and implemented standard at about 9 MB/s write speed, the others at 10-20-30 MBps are still nominally class 6.

Write speed will vary from product to product but not by storage capacity - a SanDisk Ultra II will write at the same speed (9-10 MBps, if memory serves) at 2 GB, 4 GB, 8 GB, etc.

I use SanDisk Extreme III as they allow still images to get to the card faster and allow me to be ready to shoot the next one or set more quickly. For video the card must be "fast enough" but I'm not aware of any benefit from a faster card.

I was told that class 4 (about 6 MBps) is good enough for video but I cannot vouch for the source and I don't have time to research it now. I'll leave that for the student.

And I certainly would be careful how much data you put on a card. Big cards mean you lose too much when the inevitable happens. For video I'd probably go with a few "fast enough" cards of a middling capacity rather than one big expensive faster-than-light card. No point in Extreme III AFAIK.

While we're at it, I've seen user reports that low-price cards are producing unexpected results (read: "errors") that are much more evident in video than with still images. I suspect they have lower QA targets than the premium manufacturers or that they don't test as thoroughly before shipping. I've seen that with electronics components - the cheapies are tested on a random sampling basis while the premium supplier exhaustively tests each component prior to packaging. As chip and component manufacture is less than flawless, there's always a risk in bypassing rigorous testing of each piece.

I've stuck with SanDisk and Lexar. No problems.

And I've rambled on too long.

02-26-2010, 11:06 AM   #5
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QuoteQuote:

And I certainly would be careful how much data you put on a card. Big cards mean you lose too much when the inevitable happens.
I used the think that, but someone who seemed knowledgeable thought most accidents happen while changing cards.

Crap shoot.

I doubt anything faster than Class 6 would make a noticeable difference.
02-26-2010, 11:10 AM   #6
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I would like to know the read and write speed of my camera under best conditions, and if that even approaches the threshold of the memory media.

I did notice a difference reading multiple large files from the different memory cards when connected directly to my PC (Well via the card reader).

I
02-26-2010, 12:36 PM   #7
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QuoteOriginally posted by glanglois Quote
Class info can be very misleading. As Class 6 is the fastest fully approved and implemented standard at about 9 MB/s write speed, the others at 10-20-30 MBps are still nominally class 6.
....
I was told that class 4 (about 6 MBps) is good enough for video but I cannot vouch for the source
The official body is the SD Association

From SD Association's page on Speed Class -

" ... three levels of Speed Class, class 2, 4 and 6. Speed Class 2 guarantees a minimum transfer speed of 2 mega bytes per second (MB/s), Speed Class 4 guarantees a minimum transfer speed of 4 MB/s and Speed Class 6 guarantees a minimum transfer speed of 6 MB/s. "

With Flash memory the Read speeds are normally faster than the write speeds -
for obvious reasons read speeds are the ones normally advertised.

Write speeds are much more important when it comes to performance in camera.

Most manufacturers specs are NOT clear and very vague to their write speeds.
Phrasing like 30Mb/s for read/write speeds - strictly would probably mean the read speeds are 30Mb/s, and unless explicitly stated, the write speeds are UNknown.

The current fastest SD(HC) class 6 has a minimum transfer rate of 6Mb/s -
which means the minimum Write speed has to be at least 6Mb/s to truly conform to this classification.

But any SD(HC) card at class 6 could be faster - but there is no way of being certain - unless the specs are clear - a 30Mb/s rating could mean read at 30Mb/s but write at 6Mb/s - this would still conform to class 6......

A class 4 would be less than 6Mb/s - otherwise it could be advertised as class 6...
similarly a class 2 would be less than 4Mb/s.

The much talked about Class 10 is not yet an official class at least in SDHC -
it has been said it is part of SD 3.0
which was meant for SDXC the next higher capacity standard -
but beware SD 3.0 seems like a temporary standard - as it does not really take advantage of higher capacities - which seems like the whole point of SDXC -
the standard likely to be in place for SDXC is SD 4.0 -

" The first SDXCs being released are governed by an SD 3.0 specification (which also still specifies FAT32 and thus lower capacities), whereas higher capacity and faster SDXCs are expected to follow an SD 4.0 specification, which is due to be released in spring of 2010."

Class 10 is supposed to have a minimum transfer rate of 10Mb/s -
the well known SanDisk Extreme III 30Mb/s Edition used to be marked class 6, is now marked class 10 - so it would seem reasonable to surmise that the SanDisk Extreme 30Mb/s edition even when marked class 6 probably had a write speed equal or better than 10Mb/s.

Back On Topic for this thread -
checkout this concurrent thread -

Class 10 SD Cards
02-26-2010, 02:30 PM   #8
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Thanks!

Thanks, UVT. I think I can find a way to remember that.

I would not be surprised if errors arose when cards are handled/inserted/removed. At those times the contacts are not safely tucked into insulated spots and are also susceptible to mechanical damage.

More removals/insertions = greater chance of error. OTOH, that doesn't change the "eggs per basket" viewpoint. Smaller chance of large loss or larger chance of small loss. Take your pick, I guess.

My choice is to limit my losses and swap cards at about 150-180 images. A 4GB card provides a built-in stop at just over 180, I think. That means three cards on a busy day. These images are not earning me any money so I'm willing to take the risk of 180 at a time.

Event photographers may have a different view. Anyone ???

02-27-2010, 05:36 AM   #9
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Thank you all for answers, but now knowing all that, question is which manufacturer is "sincere" with their card classification? A-data, Transcend, SandDisc, Apacer... They all are famous, so from which to buy? I decide to go with 16GB class 6.


This one looks OK...(?)


TinyURL.com - shorten that long URL into a tiny URL
02-27-2010, 10:33 AM   #10
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QuoteOriginally posted by trdi Quote
question is which manufacturer is "sincere" with their card classification? A-data, Transcend, SandDisc, Apacer... They all are famous, so from which to buy? I decide to go with 16GB class 6.
Your link now goes to an item that has been removed from eBay.

If money were no object - then the recommendation here probably would be for the SanDisk Extreme III (30Mb/s Edition) - as SanDisk is a trusted name and that series is well proven performer.

Of course the problem is that there are counterfeit/fake SD(HC) cards out there especially well known and premium priced ones - buy only from trusted vendors.

Beware of some really negative reviews of the
Amazon.com: A-DATA 8 GB SDHC Class 6 Flash Memory Card 8GSDHC6 (Blue): Electronics
hard to put trust of one's images to a product that got that kind of review -
however, I have an A-Data 4Gb Class 6 SDHC - it has been fine (so far... )

might want to look at:

Rob Galbraith DPI: CF/SD Performance Database

not all the dSLRs in th drop down menu use SD(HC)
but some of the more recent dSLRs that do are (no Pentax):

Rob Galbraith DPI: Canon EOS Rebel XSi/450D

Rob Galbraith DPI: Nikon D90

the table for the SD(HC) to computer -
Rob Galbraith DPI: Card-to-Computer: SD/SDHC Readers
although useful, really only gives the Read speeds.
02-27-2010, 11:24 AM   #11
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LOL. SD card discussions always end up becoming as complicated as the AA battery discussions we have here.

My only suggestion to the OP would be to look for reliability and compatibility as much as speed.

Not all SD cards are compatible with all cameras, including the K-x. Not all speed ratings are the same either - some cards I've (eg those from SanDisk) rated at Class 2 work faster than some I've tried that are rated as Class 6 or higher.

And as for reliability, I use Sandisk cards and have never had a problem with them.

Recommendation: get a SanDisk Extreme III or Ultra II or Video series card.
02-27-2010, 02:44 PM   #12
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I found this test of SDHC class 6 cards, and itīs wery interesting.

13 SDHC Memory Cards Reviewed : SD Memory Cards for Professionals - Review Tom's Hardware

It turns out that the "Silicon Power Class 6 SDHC, 16 GB" is the most optimal - in terms of performance and price. In performance is very close to "SanDisc Extreme II, 4GB", and by cost a lot less expensive cards. The only thing I do not know how reliable it is. Maybe it's worth taking risks ...?
03-03-2010, 11:39 AM   #13
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I order Silicon Power SDHC 16GB class 10, so I will see....
03-03-2010, 12:05 PM   #14
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Because of electrostatic discharge, always touch a common ground before touching a card. However, that's always impossible, so just touch ANYTHING metal away from the card to discharge the tribo-charging that may have built up on you.

ESD doesn't usually cause instant failure and you can't see it. But it shortens the component life.

Nutty thing is, they package these things in the worst possible material for ESD build-up--PLASTIC! Haven't checked recently, but I would bet dollars to donuts that they're not packaged in ESD-safe packaging.
03-03-2010, 04:19 PM   #15
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Hey, thank you for that useful info!

I assume you think genereal not specified on Silicon Power when you write about plastic package, because they all do it the same - unfortunately.

Thank once more for the info!
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