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03-11-2011, 11:37 PM   #46
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QuoteOriginally posted by Christine Tham Quote
Okay, here's my test results

Camera in ISO 100, Daylight WB, manual focus, continuous hi-speed mode (7fps)

Kept holding the shutter down until the buffer filled completely, and the camera no longer was able to maintain 7fps. Start timer. Stop timer when the yellow writing light stops.

PQI Class 6 16GB: 54 secs
Sandisk Extreme 16GB: 22 secs
Sandisk Extreme Pro 16GB: 23 secs

So there you have it - the Extreme Pro has no improvement over the Extreme on the K-5.

A bit disappointed, but at least I paid 10% less for the Extreme Pro than for the Extreme.
Actually I found that a full buffer on my K-5 emptied within 15 seconds with a SanDisk Extreme Pro. 23 seconds seems awfully slow to me.

03-15-2011, 02:20 AM   #47
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A bit more stats.

Finally decided to take RonHendrick's advice and inspect how many images were captured and size of images.

Camera shooting conditions: MF, ISO100, Daylight WB, 1/60s, f1.9 (FA43Ltd)

Started timer after pressing shutter button, release shutter after continuous mode slowed down (+ 3 extra images to ensure buffer is full) stopped timer when yellow "write" LED goes off.

Time taken: 22 seconds (repeatable across multiple tests, same for both Extreme and Extreme Pro)

Images taken: 28

Size of each image: 12.3 MB

Total images size: 337 MB

Effective write rate: around 15 MB/s

I have been reading up a little on SD specs.

SD UHS I mode (also called UHS104) is capable of transfer speeds up to 104MB/s (the K-5 does not support this mode)

Standard SD modes are DS (25MHz clock, 12.5MB/s transfer speed) and HS (50MHz clock, 25MB/s transfer speed).

Assuming the K5 is writing at HS mode (since the effective transfer rate is greater than 12.5 MB/s), this would imply the bottleneck is the K-5 itself, since the effective write speed is slower than either the Extreme (30MB/s) or Extreme Pro (45MB/s) max speeds.

However, it is also true that UHS I cards only guarantee a minimum write speed of 10MB/s, so perhaps both the Extreme and Extreme Pro cards are maxxed out at 15MB/s, and potentially the K-5 can write faster on other cards.

Can anyone suggest faster cards to try? I know Toshiba claims to have the world's fastest SDHC cards (up to 95MB/s read, 80MB/s write on UHS I) but they are very hard to find and nobody seems to stock them.
03-15-2011, 02:34 AM   #48
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Update: redid the test shooting in DNG rather than PEF. No real difference in either file size, number of images, or time taken.

However, I did notice the yellow LED doesn't start flashing until 1-2 seconds AFTER the shutter button has been pressed.

So the effective write rate is probably closer to 17 MB/s.

I seem to recall someone else also timed the write rate and came up with something like 18MB/s which would indicate my figures are roughly consistent.

Hound Tooth: if your K-5 is only taking 15 seconds to clear the buffer, that would suggest a write of around 22.5 MB/s which would be very impressive! Are you able to share any details of shooting conditions/camera settings?
03-15-2011, 02:42 AM   #49
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QuoteOriginally posted by Christine Tham Quote
So the effective write rate is probably closer to 17 MB/s.

I seem to recall someone else also timed the write rate and came up with something like 18MB/s which would indicate my figures are roughly consistent.
Well I'm probably the one who tested the 18 MB/s.

Your result is rather dissapointing, nothing faster then my result. So maybe that is just what it is.

The only thing different is the small filesizes (up the iso and the DNG's grow to 25 MB each), so there coult be some delay in processingtime and not all the time the camera is actually writing, but also a little waiting. Your shuttertime is a little long, but probably of no influence.

03-15-2011, 03:06 AM   #50
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As Sandisk states in the note : "* Based on SanDisk internal testing; performance may be lower depending upon host device."

Nobody knows how they tested...
03-15-2011, 03:09 AM   #51
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QuoteOriginally posted by RonHendriks1966 Quote
Well I'm probably the one who tested the 18 MB/s.

Your result is rather dissapointing, nothing faster then my result. So maybe that is just what it is.

The only thing different is the small filesizes (up the iso and the DNG's grow to 25 MB each), so there coult be some delay in processingtime and not all the time the camera is actually writing, but also a little waiting. Your shuttertime is a little long, but probably of no influence.
Thanks! No wonder you were so keen for me to check out no. of files and file sizes!

My camera settings were arbitrary (the camera was in manual mode) - the camera was also in manual focus - I just wanted to eliminate variables such as focusing time away from the test.

I think if we give the K-5 the benefit of the doubt in terms of processing time etc. it would seem the sustained transfer rate is probably around 20MB/s.

Probably quite reasonable for the system architecture in the camera. It would imply there is no point buying better cards than the Extreme (and potentially some well performing Class 10).

Looks like we probably have to wait for the next model to support UHS104 :-(
03-15-2011, 01:09 PM   #52
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QuoteOriginally posted by Christine Tham Quote
Probably quite reasonable for the system architecture in the camera. It would imply there is no point buying better cards than the Extreme (and potentially some well performing Class 10).

Looks like we probably have to wait for the next model to support UHS104 :-(
Well that was my thinking also, but hoped that with SanDisk just a little more could be squised out of it. In theory, since it is designed for pre-UHS104 it could be up to a max of 30 Mb/s but it doesn't bring it.
03-15-2011, 01:49 PM   #53
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I had been using Sandisk 4 GB Extreme III (20MB/sec) -- I shoot jpegs -- but I became a little disgruntled with Sandisk after two of the cards lost their locking tabs even though I never used the tabs. This was after about a year of regular use -- I remove the cards, download the pics and reformat the card in-camera, pretty much on a daily basis.

The cards are still under warranty, so I assume they'll be replaced, but when the tab falls off, you can't write to the card, so they're relatively useless at this time. . . I realize that I could plug half of the slot to use the card, but I choose not to as my luck would dictate that the piece would fall off inside my cam and really screw something up. . .

I also had roughly timed the K20 and K-7 at about 18MB/sec write and guesstimated that the K-5 probably was only marginally faster (if at all) writing slightly larger files in about the same times as the K-7, so I opted for some much cheaper Transcend Ulitmate (Class 10) 16GB and 8GB cards as well as an Adata (Class 10) 16 GB.

I'm a jpeg shooter and an incurable chimper, so this is my main reason for wanting a faster card. I'm finding that the Transcend and Adata cards are at least as fast as the Sandisk 20MB/s cards, so I'm a happy camper at $28.99 and $24.99 respectively for the 16GB cards and $12.49 for the 8GB, all with free shipping from Newegg. All have lifetime warranties and I've used both brands in previous cameras with no problems for years.

The only reason I'd gone with the Sandisks were that they were the only mfg that was specifying continuous write speed after the industry changed to the Class X system and "at least X MB/s" was of no help when I wanted at least 18MB/s for the K20 after being frustrated with the slow write performance of Class 6 Transcends.

AFAIC, the Sandisk Extreme cards are not worth the premium prices they seem to command.
I've only had the cards for less than a week, so I can't speak for their reliability or longevity, but as I mentioned, I've used the brands before, so I have some confidence in them.

Scott

03-15-2011, 04:19 PM   #54
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Well I was looking for something different but then again you see something you wanted to find. Someone who did tests with cards writingspeed in camera's with various camera's (no Pentax) and cards.

Rob Galbraith DPI: Nikon D90

So if the Nikon D90 tops at 20 MB/s then it is to be expected that the K-5 is topping there aswell.

I hoped for more, but it is as the rest off the bunch so that is a good thing.
03-15-2011, 06:19 PM   #55
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Reportedly the D7000 supports UHS104 but I haven't seen any reports measuring transfer speed.

I have a feeling Nikon was involved in the UHS specs so maybe they have initial exclusive rights to the technology? Or maybe they got there first.

In any case, it seems unlikely that we will see a substantial improvement in transfer speed on the K-5. :-(
03-15-2011, 06:33 PM   #56
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Did some searching, and apparently some users are suggesting that the D7000 is achieving a sustained transfer rate of around 21 MB/s [Edit: corrected from 30 MB/s - which was the transfer rate for JPEG not RAW] with the Extreme Pro, and only around 15-20 MB/s on the Extreme.

My guess is that current generation DSLRs are all hovering around the 15-20MB/s transfer speed is HS mode, and require UHS104 to break the 20MB/s "ceiling."

However, from my perspective, the D7000 is not really competitive with the K-5 for continuous mode. The D7000 can only manage 10 frames before the buffer fills at 6 fps, whereas the K-5 is clearly superior by being able to take 20-25 shots (in ISO100) at 7 fps.

Last edited by Christine Tham; 03-15-2011 at 06:51 PM.
03-20-2011, 07:12 PM   #57
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you people have weird testing methodologies, but for what it's worth:

(with SanDisk Extreme Pro)
- with lens cap on
- ISO 100
- custom image set to neutral
- white balance set to a fixed value (no fine-tuning permitted)
- RAW (not RAW+)
- all image processing options disabled (distortion correction, etc)
- image review disabled
- freshly-formatted SD card
- high speed drive mode
- manual focus
- SR disabled
- no EV comp
- DNG

Pressed the shutter button until the camera stopped taking pictures. 6 seconds later, I had taken 25 beautiful black pictures that were each 9.8 MB in size. 6 seconds after that, the status screen came back on. 3 seconds after that, the SD card light turned off. So in all, 245 MB were written to the card in the span of 15 seconds, which comes out to 16.333 MB/s. However as was mentioned before, the SD card light doesn't come on until about 1 second into the shooting burst. So keeping that in mind, that's actually 14 seconds of writing time for 245 MB, which comes out to 17.5 MB/s.

Repeated the experiment with PEF files instead. PEF files are slightly smaller than DNG files. But I still only got 25 frames before the buffer was full, and the SD card light turned off 1 second sooner (13 seconds of writing time instead of 14). So it really panned out to about the same.

Some things worth pointing out: you can disable JPGs all you want, the camera still generates a JPG file for every shot (and embeds it into the the RAW file). So image processing still happens every time, regardless of your settings. Also, the embedded JPG is 16MP and heavily compressed, even if you set JPG files to be only 2MP. There's a lot more involved here than raw file writing speed. That's why I set the white balance to a fixed amount, that way the camera isn't doing its own WB calculations.

In conclusion, this was by far the most boring and pointless testing I've ever done. I gained no conclusions, other than to prove to myself that this SanDisk Extreme Pro card makes my K-5 much more responsive than my Patriot Class 10 card. And I certainly didn't need to waste all those shutter actuations to figure that out.
03-20-2011, 08:55 PM   #58
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QuoteOriginally posted by Hound Tooth Quote
Pressed the shutter button until the camera stopped taking pictures. 6 seconds later, I had taken 25 beautiful black pictures that were each 9.8 MB in size. 6 seconds after that, the status screen came back on. 3 seconds after that, the SD card light turned off. So in all, 245 MB were written to the card in the span of 15 seconds, which comes out to 16.333 MB/s. However as was mentioned before, the SD card light doesn't come on until about 1 second into the shooting burst. So keeping that in mind, that's actually 14 seconds of writing time for 245 MB, which comes out to 17.5 MB/s.
Thanks for confirming that your camera is also maxing out at around 17 MB/s, which is roughly the same as what I'm getting on both Extreme and Extreme Pro.

Given that the K20D can reach a figure of 18.4 MB/s on the old Extreme III card (figure published in the Japanese "Kameraman Series Pentax K20D owner's book") this would confirm that firmware 1.03 is slightly slower than 1.01, and indeed older cameras.

In any case, well short of the Extreme Pro's claimed speed of 45 MB/s.
03-20-2011, 10:24 PM   #59
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QuoteOriginally posted by Christine Tham Quote
In any case, well short of the Extreme Pro's claimed speed of 45 MB/s.
That is the cards' rated transfer rate, nothing to do with the camera. Can any camera do 45 MB/s? If not then there is not much need to buy such high speed cards except maybe for video?
03-20-2011, 10:43 PM   #60
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QuoteOriginally posted by ozlizard Quote
That is the cards' rated transfer rate, nothing to do with the camera. Can any camera do 45 MB/s? If not then there is not much need to buy such high speed cards except maybe for video?
These cards are overkill for video. Video on the K-5 only requires 5-10 MB/s, which is roughly half of what the K-5 is capable of writing.

The sole purpose of these cards are for those who like to shoot in continuous mode. The K-5 is probably the first Pentax camera that has a decent continuous mode, far better than Canikon models in the same price point. Pity Firmware 1.03 hobbles the write rate slightly - I'm hoping this will get fixed but not holding my breath.

Currently the only cameras that can write faster than 20 MB/s are the pro models, which can do 30-40 MB/s on compact flash. I have not seen any SDHC/XC based cameras that has managed to achieve that yet.
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