Which SD card for the D7000

Discussion in 'Nikon' started by richard_driscoll, Apr 27, 2013.

  1. Please excuse me if this has been addressed recently but I don't think it has.
    I've been wondering which SD cards to buy for my new D7000. Specifically which ones will offer decent speed without costing too much. Rob Galbraith has recently done some experiments:-
    http://www.robgalbraith.com/bins/camera_wb_multi_page.asp?cid=6007-12454
    Sandisk Extreme Pro 95MB/s is fastest, running at just over 26 MB/s when writing raw files.
    For less money Sandisk Extreme runs at around 23 MB/s, also for raw files.
    I thought I'd probably go the the less expensive Sandisk Extreme; it's probably good enough for my purposes.
    However I just realised something interesting. The display in the viewfinder showing shots before buffer fills (r10, r15 etc) is not fixed for any particular quality setting; it seems to be determined by the camera determining the card write speed. All my cards are fairly slow Sandisk Ultra and for 12 bit lossy compressed the display shows r11 whereas the manual seems to be saying that with a Sandisk Extreme Pro it would show r15 (table on page 320).
    So my question is this:-
    Can anyone please tell me what their display shows for 12 bit lossy compressed NEF with a fairly new Sandisk Extreme card and also for a Sandisk Extreme Pro card. It seems a fairly easy way to confirm just how much slower the non-Pro version is.
    Hope that all kind of makes sense ...... :)
     
  2. Richard, I think you're mistaken about the function of the display.... The amount of photos that fits into the buffer does depend on the quality settings. It is not a fixed amount independent of that. Plus there are other settings (Active D-Lighting for example) that can influence the amount of photos that can fit into the buffer. That figure shown there is totally independent from the write speed from buffer to memory card, though.
    So, what you're suggesting to test will not demonstrate what you hope it should, I'm afraid.
     
  3. ShunCheung

    ShunCheung Moderator

    The timing is great that this question comes up. Yesterday, I tested several SD memory cards on the D7100 to check out their write speed, and I also checked them out on the D7000 for comparison.
    The image below shows the 5 cards I usually use in these days. In particular, I tested the middle three on both the D7000 and D7100. While the faster cards clearly show an advantage on the D7100, which is UHS 104 compatible (Ultra High Speed: http://en.wikipedia.org/wiki/Secure_Digital#UHS_Speed_Class) and therefore can take full advantage of the (theoretically) 95MB/sec transfer rate on the SanDisk Extreme Pro, the D7000 is not.
    In fact, it takes the D7000 about 0.6 sec to write a 14-bit, lossy compressed (i.e. not lossless) RAW file onto either the 95MB/sec Extreme Pro or the 45MG/sec Extreme. On the slower 30MB/sec Extreme, it is about 0.8 sec. If you would like to squeeze out the small difference, go with the 45MB/sec card over the 30MD/sec, but there is clearly no point to pay for the 95MB/sec type for the D7000. And as Wouter points out, the number of remaining frame counter is not affected by which type of card you have in the camera. I just put those cards into my D7000 again to verify.
    Therefore, my conclusion is essentially the same as Rob Galbraith's. On the D7000, there is no point to buy the expensive high-speed cards. The D7100 is a totally different story.
    00bau4-534389584.jpg
     
  4. Wouter,
    At first I thought the same as you; namely that the display buffer estimate would only be affected by quality settings, D-lighting etc., but I have changed my view.
    Logically the number of frames one can shoot before the camera slows will also depend on the speed of the card. Since the buffer is a FIFO (of fixed size) data is flowing in at a high rate and out at a lower rate to the card. If the card is very slow virtually nothing will get written out before the buffer fills. Conversely if the card is almost as fast as the camera processor then the buffer will take a long time to fill since the *net* inflow will be very low. If the card is faster than the camera processor the card will never fill which is the case when shooting small JPEGS.
    If you look at the table on page 320 (memory card capacity) you'll find a column headed buffer capacity but I don't think it is a true capacity; I believe it is an estimate of the number of shots before the buffer fills up.
    Anyway if we can get the figures for a fast card in a D7000 we'll see, since I expect them to be higher than the r11 for my slow Sandisk Ultra.
     
  5. Hi Shun,
    My posting crossed with yours so I only just saw it. Please what does your D7000 display show for 12 bit lossy compressed NEF with a Sandisk Extreme Pro?
    Also is your understanding of the manual the same as mine; that it's giving an estimate of shots before buffer fills up?
    Would you also agree with me that the D7000 should write about 2 12 bit lossy frames per second?
    Thanks all.
     
  6. ShunCheung

    ShunCheung Moderator

    Richard, here is some RAW data for you to digest. The test procedure is the same for the D7000 and D7100, as I described on the following thread yesterday: http://www.photo.net/nikon-camera-forum/00bZtQ However, on the D7100, I tested both 12-bit and 14-bit RAW.
    You can watch the clock on my i-Pad under the stop watch mode. Again, on the D7000, I was using 14-bit, lossy compressed RAW. Here I am only showing the first 18 frames. After 20 frames or so, the D7000 slows further down to somewhere between 0.7 to 1.0 second to write each frame; I would take 0.8 or 0.9 as an average.
    [​IMG]
    00bauH-534395584.jpg
     
  7. ShunCheung

    ShunCheung Moderator

    with 95MB/sec Extreme Pro
    Please click on the link below for a larger image.
    [​IMG]
    00bauI-534395684.jpg
     
  8. ShunCheung

    ShunCheung Moderator

    Please what does your D7000 display show for 12 bit lossy compressed NEF with a Sandisk Extreme Pro?​
    My D7000 shows 11 frames (r11) remaining for 12-bit lossy compressred RAW, with the Extreme Pro or any other SD card I put in there. I just tried that. Again, that counter has nothing to do with the type of card. If I switch to lossless compressed and 14 bit, it goes down to 10 frames.
    I also switched off Active D Lighting, long-exposure noise reduction, and high-ISO noise reduction, and my ISO setting is 100. Some of those settings can affect your buffer size, especially long-exposure noise reduction.
     
  9. Thanks for that Shun. Same as my slow old Sandisk Ultra. It confirms what I originally thought and Wouter and you have correctly pointed out. It looks as if the display is just approx. (buffer size)/(estimated file size). The figures in the manual must therefore be an estimate of "frames to overflow buffer" with the card under test not of buffer capacity which is what Nikon say.
    From your D7000 tests above it looks as if both cards allow about 12 frames before the camera slows which is what the manual quotes. Interestingly you've actually caught the display on the change in a few frames.
    It now all starts to make some kind of sense.
    12 bit lossy. Display shows 11 estimate is 15 (we can write out a few small frames before the buffer fills up).
    14 bit lossless. Display shows 10 estimate is 10 (can't even get one out before buffer fills up).
    Small frames mean camera runs longer before buffer fills *and* get written out faster.
    Guess I'll go with Sandisk Extreme either 30 or 45 MB/s. According to the Sandisk Web page 4 & 8 GB are 30 MB/s. Larger cards are 45 MB/s.
    Could you tell your Sandisk friend that it's confusing the way they apparently change the specs and keep the names the same. I have 3 Sandisk Ultras. One says nothing, one says 15 MB/s, and one says Class 4. I *think* they are all probably the same speed but I'm not sure .....
     
  10. I posted too soon. If I turn on distortion control (quoted as a slowing factor which ADL is not) the JPEG buffer estimate in the viewfinder goes down (and the maximum burst goes down too). I guess the distortion processing is done between the buffer and the card write process which makes the buffer fill quicker since frames are written out slower. I give up on understanding exactly what the viewfinder display is showing!
     
  11. But, Richard, what you find makes sense - distortion control is a slowing factor, as it is (heavy) post processing done while the image is in the buffer (to me, it makes sense this has to happen at that time, as the operation is too intensive to do "on the fly"). So, don't think of the buffer as only a "cache for SD-card writing operations", there is a bit more going on there.
    While the buffer is FIFO, it is FIFO-one-file-at-a-time, as far as I've come to understand. Once it starts writing, it's not like it clears 1MB of the buffer once it wrote 1MB. Plus, if files are "edited" while in the buffer, it will need to reserve space for writing the edited file in the buffer - and that reduces the available number of shots in the buffer.
    Hope my understanding has been correct so far, and it yes, I hope that helps understanding a bit what happens :)
     
  12. I gather JPEG compression 'style' regarding either quality or size preference affects speed.
     
  13. Mike,
    Yes, if you choose 'quality' rather than 'size' then the files are larger on average and that may be the reason why things can get slower. My understanding is that 'size' tries to keep the file sizes the same but hard to compress files may then be of lower quality than easy to compress ones. If you choose 'quality' then hard to compress files are allowed to grow in size while maintaining quality.

    Wouter,
    I just looked at the manual for my old D40. The column which in the D7000 manual is headed 'Buffer capacity' is headed 'Burst capacity' and the footnotes say:-
    'Maximum number of frames that can be taken before shooting stops. Actual number of frames can vary with make of memory card. Additional photographs can be taken as soon as enough memory is available in memory buffer'
    I don't why Nikon changed the wording in the newer manual since I think the D40 description is much more accurate.

    Shun & Wouter,
    Thanks for all the help.
    For the benefit of anyone reading this post in future the conclusions are:-
    To get the best performance with a D7000 a Sandisk Extreme (or equivalent) SD card is virtually the best available; a Sandisk Extreme Pro (or equivalent) is almost certainly not justified.
     
  14. Richard, I just saw your post, hence the many months since you posted. I have always used Sandisk Extreme Pro SD cards with great success and no complaints. Lately, I have been using 8GB cards. I own a couple of 16GB SD cards, but don't use them because I don't want so many images on one card. I suggest changing cards by the time 70-80% of the card space is filled. Why risk losing images if the card goes bad for any reason? I transfer my images to a storage device or my computer daily and reformat the card. The D7000, and many other cameras, has two SD card slots, so 8GB is 16 GB anyway if you use the second card for roll over. My concern is getting images off of my cards as fast as possible. Hope this is helpful. Larry
     
  15. Larry,
    Thanks for that. There's nothing wrong with Extreme Pro cards; it's just that the conclusion was that the D7000 (unlike the D7100) is not able to make best use of them with the plain Extreme being virtually as fast and costing less.
     
  16. ShunCheung

    ShunCheung Moderator

    I hope people understand that traditional computer hard drives that use mechanically spinning magnetic discs is the most vulnerable part of any computer system. However, memory cards, be it CF or SD, are solid-state devices that are much much safter. Therefore, unless you use modern solid-state drives (SSD) on your computer, storing your image on a computer/traditional hard drives is actually much more dangerous (due to hard drive failure) than leaving them on an SD card.
    In these days, I use a 64G SD card on my D7100 in conjunction with maybe another 16G or 32G in the backup mode, such that each RAW file is written onto both cards. I take the smaller-capacity card out and upload images from that to the computer, and I backup to 2, 3 different hard drives. The 64G stays inside the camera and once in a while I upload from that also onto a different hard drive. When I travel, I use a couple of 64G cards and they can store all images from the trip. I don't format them until I get home and uploading everything (for a second time). 128G would be even better, but those cards tend to be very expensive.
    I would much rather not juggle too many different memory cards, especially when you travel, it is easy to lose or physically damage those small SD cards that are very thin. The card that is inside your camera is the safest one, unless your camera gets stolen. Inside or outside of a camera, a card that is physically lost (no longer in your pocession) essentially means those images are gone forever, and I have seen people losing memory cards a number of times. On the other hand, the chance for an electronic damage on a hard is quite rare, and even when that happens, there is still a chance for recovery (although professional recovery can be expensive, but if you have important images, it is still worth it). When you use the backup mode on the likes of D7000, D7100, D600, D800, etc. to write to two cards simultaneously, it is almost impossible to lose images due to card failures.
     

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