Memory card speed vs camera write speed

Discussion in 'Photography & Video' started by Goobers, Dec 3, 2011.

  1. Goobers

    Goobers Member

    Joined:
    Feb 3, 2010
    Messages:
    3,484
    Location:
    Sutherland Shire, NSW
    I want a faster memory card, or at least I think I do. What I want to know is if a camera's ability to take multiple shots consecutively for extended periods of time is limited by the camera or the memory card.

    I have a 7D and use a 16GB sandisk 60mb/s card, the problem I'm having is when shooting at its max 8fps I can only get 1 second of photos out before the buffer on my camera fills and starts to slow the frame rate.

    Does the photo files go through the camera processor at a speed that can limit the transfer regardless of the speed of the card, or is the camera processor fast enough for transfer speed issues to be negligible and therefore the fault of the card speed.

    I can easily get around this by selecting a smaller size RAW file, but I dont want to. I shoot alot of burst runs at the local cable ski park and only one or two out of a burst run will make it to the editing stage. and when the selected photo does get to the editing stage I dont want a small RAW to work with, I want all the MP i can get as cropping is usually mandatory for a better composition.

    I'm also limited to what I can get, at regular settings I can get the begging or the end of a jump/trick, not the whole thing. which sucks.

    Cliffs:
    -want to know if the cameras buffer is slowing the transfer of photos to the memory card, or if its the memory card speed that limits it.
    -if its the memory card, what is a good reliable brand of 90MB/s or faster cards.

    The cards dont even have to be 16 GB, the cheapest I've found 16GB 90MB/s sandisk cards for is $180, however I'd prefer cheaper if available, so it doesn't have to be sandisk or even 16GB. 8GB would be fine.
     
  2. th3_hawk

    th3_hawk Member

    Joined:
    Jun 4, 2005
    Messages:
    1,730
    Location:
    [VIC] Eastern Suburbs
    Hopefully someone can help out with the max possible WRITE speed of the 7D, but at ~25mb for a RAW image, your 60mb/s card can only manage 2.4 images per second if it can indeed be maxed out.

    A quick google turned up this thread you might want to look at:

    http://www.pixtus.com/forum/equipment-talk/132625-canon-7d-write-speeds.html

    Also the wiki here:
    http://en.wikipedia.org/wiki/Canon_EOS_7D

    seems to say 100mb/s cars can help...

    Seems it might be worth a bash with a faster card. Maybe take the camera into a decent shop and test the cards before purchase to see if they actually live up to the paper numbers and will help your situation.
     
    Last edited: Dec 3, 2011
  3. OP
    OP
    Goobers

    Goobers Member

    Joined:
    Feb 3, 2010
    Messages:
    3,484
    Location:
    Sutherland Shire, NSW
    Cheers, I just found cheaper 90MB/s cards on adorama, but the postage is ridiculously prohibitive for such a small item. $60 postage for a $90 CF card...I dont even.
     
  4. checks202

    checks202 Member

    Joined:
    Oct 2, 2004
    Messages:
    684
    Location:
    Sydney - CBD
    So how does one get above 8Fps using that theory? I thought there was a buffer.
     
  5. OP
    OP
    Goobers

    Goobers Member

    Joined:
    Feb 3, 2010
    Messages:
    3,484
    Location:
    Sutherland Shire, NSW
    Well you cant get past the maximum FPS of the camera for photos, what Im trying to do is get the cameras maximum fps at full res for more than one second. currently unattainable.

    I wonder if it would be even quicker if I just hooked my camera directly into my laptop and shot my photos tethered, surely the pc connection would have a faster write speed than any CF card.
     
  6. th3_hawk

    th3_hawk Member

    Joined:
    Jun 4, 2005
    Messages:
    1,730
    Location:
    [VIC] Eastern Suburbs
    I couldn't recall the actual numbers, but stolen from here talking transfer rates of different tech: http://www.barefeats.com/usb2.html

    So in short, nope, still boned given the interface you have to work with, even assuming you could hit 100% performance over USB 2.0, your current memory card does that.

    A *FAST* memory card is your best (and only) option.
     
  7. Sir.Eos

    Sir.Eos Member

    Joined:
    Feb 17, 2009
    Messages:
    917
    Location:
    Glenelg, Adelaide
    The camera buffer figures are available for just about every camera, of how many shots they will shoot before filling the buffer in just about every resolution etc etc. However these are done under optimal lab conditions at max shutter speed etc and thus are usually unrepeatable in the real world, only camera I've seen actually live up to these numbers in the real world is my 1 series, that thing is amazing at burst.
     
  8. Asako

    Asako Member

    Joined:
    Jun 6, 2008
    Messages:
    1,135
    The really high speed is jpeg mode or lower MP. You're not gonna get 8 FPS out of 25Mb RAWs, though higher speed cards obviously help. I recently picked up some 45Mb/s extreme pro SD cards and they make a noticeable difference for me with my K-r, though Pentax currently doesn't have any cameras that can write at > 30Mb/s, so anything over that is just bonus for USB3 reading, not camera's shooting. Not the case with other brands/models and CF cards.
     
  9. Bern

    Bern Mind the gap!

    Joined:
    Jun 27, 2001
    Messages:
    5,183
    Location:
    Brighton, QLD
    After some unscientific testing with my 7D at the same burst setting with a SanDisk Extreme Pro 90 MB/s, I get 4.5 seconds of shooting before the buffer fills, then it's shoot two, pause to write, shoot two more, etc...

    Edit: Just did it again and counted 25 shots before the write pause so maybe it's 3.5 seconds, might try it with my phone timer instead of my watch.

    Edit2: Yep, with phone stop watch it's about 3.5 seconds, get a slightly slower 22 frames in the same time with a Lexar Pro 600x
     
    Last edited: Dec 3, 2011
  10. OP
    OP
    Goobers

    Goobers Member

    Joined:
    Feb 3, 2010
    Messages:
    3,484
    Location:
    Sutherland Shire, NSW

    I also just did some tests with my 7d hooked into my laptop using EOS Utility.

    I can get 26 frames before reaching buffer (when hooked into my laptop) on mRAW, and 21 frames on RAW. that is saving to the Lappy hdd, not writing to the memory card.

    Its much faster than what I was able to get before, however I was shooting RAW+S.jpg, I've changed to just RAW and noticed a considerable speed increase. I do enjoy using the S.jpg as a preview feature on my pc as I cant view RAW files from windows picture viewer. but if its causing me to miss the shot then consider it gone.
     
  11. Bern

    Bern Mind the gap!

    Joined:
    Jun 27, 2001
    Messages:
    5,183
    Location:
    Brighton, QLD
    I shoot in RAW all the time, there is a codec you can download from canon that allows viewing RAW images in windows picture viewer and IrfanView can also render CR2 images.
     
  12. DJ_Hippster

    DJ_Hippster Member

    Joined:
    May 22, 2003
    Messages:
    557
    Location:
    NE Adelaide, Australia
    You can get a RAW thumbnail viewer plugin so you can preview the RAW files in Windows Photo Viewer.

    Also the 7D has an internal CF card slot capable of up to 100MB/s write.

    So a 600x card is almost a given to utilise the camera to its full potential :)

    However in saying that, shooting in RAW you will always hit the buffer as the camera just cannot save data fast enough.
     
  13. OP
    OP
    Goobers

    Goobers Member

    Joined:
    Feb 3, 2010
    Messages:
    3,484
    Location:
    Sutherland Shire, NSW
    - Windows 7 32-bit version (64-bit version is not supported.)

    Sigh, forever a 64bituser, back to the drawing board.

    Thanks DJ, some useful information in this thread.
     
  14. Bern

    Bern Mind the gap!

    Joined:
    Jun 27, 2001
    Messages:
    5,183
    Location:
    Brighton, QLD

    It works on 64 bit, I know because I use it to view CR2 images in windows picture viewer.
     
  15. DJ_Hippster

    DJ_Hippster Member

    Joined:
    May 22, 2003
    Messages:
    557
    Location:
    NE Adelaide, Australia
    I'm using it on 64bit :)
     
  16. checks202

    checks202 Member

    Joined:
    Oct 2, 2004
    Messages:
    684
    Location:
    Sydney - CBD
    Mmm,

    With the new Canon coming out.. Hypothetically tethered via Lan it should break the 90MB/s rate?
     
  17. Bern

    Bern Mind the gap!

    Joined:
    Jun 27, 2001
    Messages:
    5,183
    Location:
    Brighton, QLD
    Isn't the new canon a video camera?
     
  18. bueller

    bueller Member

    Joined:
    Jan 13, 2009
    Messages:
    2,123
    Location:
    Perth
    Pretty sure he's talking about the 1Dx
     
  19. Nafe

    Nafe Member

    Joined:
    Dec 25, 2002
    Messages:
    4,064
    Location:
    North Shore, Sydney
    can I just ask.... why do you need 8fps shooting full RAW?
     
  20. OP
    OP
    Goobers

    Goobers Member

    Joined:
    Feb 3, 2010
    Messages:
    3,484
    Location:
    Sutherland Shire, NSW
    First post, 4th paragraph.
     

Share This Page