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Old Nov 8, 2008, 11:00 PM   #11
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Acording to the information on Lexar and Sandisk card boxes in my posession, 1X = 150KB/sec.

Lexar 4X = 600 Kb/sec, 12X = 1.8 MB/sec, 40X - 6.0 MB/sec.

Sandisk Extreme and Ultra II, 9 MB/s - 60X, 10 MB/s = 66X, and Extreme III 20 MB/sec = 133X

so a 30MB/sec card ahould be almost 200X

The Extreme III cards (2GB) are newly purchased under a recent Sandisk rebate program, have a black label and the label is clerly marked "20 MB/sec" (and is marked as Class 6). If there is a 30 MB/s version it would be marked as such.
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Old Nov 11, 2008, 4:51 PM   #12
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snostorm wrote:
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Has anyone done any comparisons between the 20 and 30 MB/sec cards to see if there is any additional speed advantage? I realize that the limiting factor will likely be the max write speed of the camera, and I'm willing to spend the money to upgrade to the fastest cards if there is a noticeable improvement in performance.

Any info would be greatly appreciated.

Scott
Scott, I don't have any information but I think I do have the variety of cards to perform a test with the k20d. My card arsenal includes three 4 gig Extreme III SDHC cards, 2 OCZ 4 gig SDHC class 6 cards, and a 4 gig SD 150x card. I am on vacation in KY this week but I will try to run a test soon. I am interested both in how fast the buffer clears but also if the number of frames before you fill the buffer changes with the more expensive cards.

Tim
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Old Nov 12, 2008, 12:55 AM   #13
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NonEntity1 wrote:
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Scott, I don't have any information but I think I do have the variety of cards to perform a test with the k20d.* My card arsenal includes three 4 gig Extreme III SDHC cards, 2 OCZ 4 gig SDHC class 6 cards, and a 4 gig SD 150x card.* I am on vacation in KY this week but I will try to run a test soon.* I am interested both in how fast the buffer clears but also if the number of frames before you fill the buffer changes with the more expensive cards.
Hi Tim,

Good idea -- If you can figure out an easily copied methodology, you can start a new thread, and any others who are interested can duplicate the test with their cameras and add new combinations. We can build a small database of comparative speeds and make some conclusions.

. . . well that might be getting a little carried away -- I've got a few cards and bodies, so I could test them and report. . .

I'm thinking of buying 1 ea of the 20MB/sec and 30MB/sec Extreme IIIs and seeing if there's any difference. I'm sure that either will be faster than the Transcends that I'm using.

Scott
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Old Nov 12, 2008, 8:47 AM   #14
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OK, I have been researching this on line and from what I found the new 30MB/s SanDisk card is the fastest out there, but is limited by the device it is used in. USB II card readers seem to slow it down from the tests I have read and from what I understand the DSLR it is used in has to be designed to support the 30MB/s speed or you will see no advantage over a 20MB/s card.

The Nikon D90, is the first DSLR camera to support SanDisk Extreme III 30MB/s Edition SDHC cards at increased performance and I can find no mention of any other camera listed that is designed to take advantage of the faster speed.

I will be interested in Scott's test to see if in real world shooting the SanDisk 30MB/s card is any faster than the older and cheaper 20MB/s SanDisk card.



Tom
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Old Nov 12, 2008, 10:09 AM   #15
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ive got 2 4GB extreme III cards, i got them from different places, but one is from amazon UK, and they are identical in every way, both came with a little pouch and a small sqaure card reader and mini cd. on the box it says 20mb/s* 133x class 6.

i must say they are very fast, reading off the cards seems as fast as reading from the hard drive, im not sure if you would notice much difference from the 20mb one to a 30mb one, certainly not while using in the camera as no matter how many shots i take it seems only seconds to clear the buffer.

grab yourself a bargain
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Old Nov 12, 2008, 1:04 PM   #16
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snostorm wrote:
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I've been using Transcend Class 6 4GB SDHC cards (my thinking at the time was that Class 6 seemed to be the fastest of the then relatively new SDHC cards) and find the write speeds of the K20 a bit slow for effective chimping, which is important to my shooting workflow.

I just did a very unscientific (seat of the pants) test with a Ridata 1GB card (spec says 133x -- so @ 20MB/sec) against my Transcend Class 6 ("at least" 6MB/sec) shooting 5 frames contiuous ***jpeg at the same subject, and the Ridata was noticeably faster clearing the buffer of the K20 -- about 2-3 sec vs 4-5 sec. So it looks like I'll be spending some money to upgrade to at least 20MB/sec cards.
That's odd. Actually, the Transcend Class 6 SDHC cards tend to test as quite fast.

Here are some benchmarks of a couple of cards. Click on the larger size of the first graph to see read/write performance of an 8GB Transcend Class 6 SDHC card (around 14MB/second write and 19MB/Second read with larger block sizes):

http://www.tabletpcreview.com/default.asp?newsID=1096

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Old Nov 13, 2008, 4:28 AM   #17
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bilybianca wrote:
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I've never bothered about the writing speed in camera, whatever card I have used it has been good enough for what i shoot.

But when I started using 2 GB cards (SanDisk Ultra II)in my K20D I was (and am) annoyed by the very slow download from card to the internal hard drive, using the built-in card reader in the computer. But I have thought "well, I can always have a cup of coffe, this is part of the game".

At the Munich airport I found a package deal on two 4GB cards (SanDisk Ultra II) with card readers which was too tempting, so I bought them. Finding that the download was very much faster when I used the card reader that came with the card, connected to a USB port. About 5 minutes for 4 GB vs 20 minutes for 2 GB using the internal reader.

I won't even try to understand why, but guess what I'll use for the future!

Kjell
Perhaps the internal card reader was only USB v1 whereas to read SDHC Cards, card readers have to be compatable with the HC format & would support USB v2 thus making a considerable difference to the transfer speed.

On a different note, why the obsession with speed, when the camera write speed is much less than the capability of the card. OK, if you've got a 32GB card filled to the brim, you want the data transferred to the PC in reasonabe time, but that's a awfull lot of images.
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Old Nov 22, 2008, 5:24 PM   #18
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Hi All,

OK, ordered and got the cards, but not what I expected. I had gone on Amazon a couple of times to see what was being offered, and the prices were significantly lower than my normal sources for this type of thing, so I decided to order through them. The featured suppliers were different every time I went there, so I waited for the best price to be offered on the two different cards from the same supplier. I was a littel nervous about getting knock offs, but felt that if I bought both cards from the same supplier, I'd not only save shipping, but also would have a better chance of getting actual Sandisk cards. Isn't buying on the net fun?:roll:

Anyway, the Black Label is supposed to be 30MB/sec , and the White Label is supposed to be 20MB/sec . I ended up getting two Black Labels, one in retail packaging with a warranty sheet,recovery software on a mini CD, and a little carry pouch, and the other in just a plastic case, which was larger than the the case in the retail packaging.

There is nothing regarding speed except for the Class 6 printed on either card and the retail box says 20 MB/sec. Now that I look on a number of sites, most aren't specifying 30 MB/sec for the Black Labels (but at least one still does). I don't think it would be very fruitful to try to get the two exact cards that I thought I was ordering, and any price differential is probably in my favor.

I had hoped to be able to see if the K20 would write faster with a 30MB/s card than with a 20MB/s card -- so much for that. . .

Bottom line -- The Sandisk Black Label 4 GB Extreme IIIs (whatever speed they actually are)-- I did test both -- are just a touch faster than the 133x Ridata 1 GB card that I mentioned in my previous post, and almost twice as fast as the Transcend Class 6 4GB cards that I have been using.

All these were tested with a very unscientific and subjective method (I seem to have an alergy to measurebating)-- I took a continuous burst of 5 *** jpegs of the same section of blank white wall, started counting on the last of the shutter actuations, then counted using the tried and true method of "(one) one thousand, (two) one thousand), and watched the "working" light on the back of the camera (K20) until it went out. I repeated the test a couple of times with each card to make sure that I was reasonably consistent.

With the Transcend 4 GB Class 6 SDHC card, the light went out at (four) one. . . (I'll call it @ 3.4 seconds). With the Sandisk Extreme III Black Label Class 6 SDHC (I'll assume 20MB/s) the light went out at (two)+ . . .(call it @ 1.25 sec). The light went out at (two) one. . .(call it @1.4 sec) with the Ridata 133x 1GB SD card. For me, the actual times are irrelevant, I just needed a feel for how fast they accomplished the task relative to each other.

I normally have my cameras set to not display an instant review on the LCD because I find the light from the LCD distracting while my eye is at the viewfinder. I usually have enough to worry about while shooting birds. I like to bring the camera down after the first couple of shots and hit the review button on the way down just to make sure I haven't messed up the settings -- I've had too many shoots where I assumed that everything was alright, only to find that I just took 20 great shots of a GBH, but the little stream of sunlight on the white patch on its head were totally blown out, ruining all the shots. I use the blinking over/under display, and can immediately see if there are any problem areas that I need to compensate for. This has to be quick -- birds don't usually show a lot of patience, and with a long lens, it sometimes takes quite a while to reacquire the subject in the viewfinder, so sometimes every second counts.

With the K10 and jpegs, the pic is usually already being displayed by the time that I can focus on the LCD. With the K20 and the Transcend Class 6 4GB cards, I often had to wait up to a couple of seconds for the images to write before I was able to chimp a shot. . .frustrating . . . Now the review comes on just as I bring the camera down -- and the K10 takes about the same amount of time with the slower Transcend cards so the two different models will behave about the same in the field.

I'm pretty happy with the performance of these Extreme III black label 4GB cards, and they were cheap, averaging around $20 USD each due to the one being a retail pkg. If I have the opportunity to pick up one marked 30MB/s for a good price in the future, I'll probably test it just for information sake, but I'm thinking that the write speed is the limiting factor here, and I think that it won't be much, if any, faster.

I know that this all seems kinda trivial to many, but with me, I need to push the capabilities of the K20 a bit to make up for what it lacks in AF and burst speed. I'm very committed to using Pentax DSLRs for my birding pursuits, mainly for IQ, ergonomics, and budgetary constraints, not to mention my investment in glass, so I need to get every edge I can.

Scott
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Old Nov 22, 2008, 7:34 PM   #19
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A visit to the Sandisk website SD Extreme III page ( http://www.sandisk.com/products/Prod...7&tab=1#review ) provides the answer. Clicking on the various boxes on the right side of the page shows that there is one 2 GB card, 2 cards each at 4 and 8 GB, and one at 16 GB. All are black label. The 2GB is marked 20 MB/s, the 4 &8 GBs are either unmarked (cheaper) or marked 30 MB/s (more expensive), and the 16 GB is 30MB/s. If the unmarked cards are marked 20MB/s on the boxes, then they offer both 20 and 30 speeds in 4 & 8 GB sizes at different prices, so you get what you pay for. There are no white label cards now.
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