Some informal testing with a fast card on an E-M1

Discussion in 'Olympus Cameras' started by zathras, Oct 30, 2014.

  1. zathras

    zathras Mu-43 Regular

    161
    Jul 13, 2014
    Waikato, New Zealand
    Chris Nielsen
    Hi all.

    Until recently I did not even realise I had a slow SD card. I have been having problems with slow flushing of me E-M1 buffer and after reading a thread on cards I looked into the ratings on the one I had, turns out it is rated at 10 mb/s. No wonder the poor camera too so long to clear the buffer!

    I ended up purchasing a Sandisk Extreme Pro 64GB 95 mb/s card from B&H which arrived today, so of course I had to run some informal tests on it, I found the results quite startling, so I thought I would post in case anyone else is in the same situation.

    I compared my 10 mb/s rated Apacer 16gb card to the Sandisk, and my download tests were conducted on my 2011 Mac Mini with built in SD reader which is connected via PCIe and pushing files onto an ancient Intel SSD which a long time ago I tested at a write speed of 150 mb/s.

    Camera was set to base ISO, RAW only mode, shutter speed of 1/1000, manual focus, drive speed set to continuous L / 6.5 fps. First test was shooting only as long as the camera could maintain 6.5 fps and then stopping. Second test was 30 seconds of continuous shooting. I did test 10 fps mode and the results were identical in terms of number of images and write speed.

    Apacer card: 6.5 fps lasted for 5.5 seconds giving 35 images, then a steady 0.69 fps until the 30 second mark. Total of 52 images captured in 30 seconds. 47 seconds to clear buffer. Approx 11 mb/s

    Sandisk card: 6.5 fps lasted for 8 seconds giving 53 images then a steady 2.9 fps until the 30 second mark. Total of 118 images captured in 30 seconds. 12 seconds to clear buffer. Approx 90 mb/s

    In my downloading test, I was able to achieve 36 mb/s from the Apacer with Image Capture. The Sandisk card gave me approx 50 mb/s with Image Capture. Lightroom and Aperture were slower. The card reader should be capable of much faster speeds, I will do some more testing and see if I can't figure out why it's not as fast as I would like, but 50 mb/s is Ok for now. I suspect the SSD is the bottleneck but I can't get my Blackmagic test program to work under OS X 10.10 to test it.

    When I shoot action it's a pain to have a long wait before I can get into playback mode, the faster card will sure help with that. Also, 2.9 fps is fast enough to be practical for what I shoot, so I can just keep shooting and it will keep up. Awesome! Also interesting was high ISO (6400 tested) writes are slower, 60 mb/s instead of 90 mb/s.

    Hopefully this is of interest to someone out there, maybe the most useful finding is that in my tests at least, the E-M1 will use a 95 mb/s card at very close to full speed so if you are tossing up getting a 45 mb/s or a 90 mb/s card, at least now you know that the camera will happily get full speed out of the faster card. I would love to test a 250 mb/s card in it next!

    Cheers,

    Chris
     
    • Like Like x 3
  2. Mdb2

    Mdb2 New to Mu-43

    8
    Nov 13, 2014
    Thankyou for the comparisons, I wish that all manufacturers would quote there cameras read write speeds it would save a lot of bother getting the slower cards. Only to upgrade later! Please let us know when you get a faster card
    Kind regards mike
     
  3. zathras

    zathras Mu-43 Regular

    161
    Jul 13, 2014
    Waikato, New Zealand
    Chris Nielsen
    I would love to get a faster card. It would be nice to get a smaller card that is really fast as I sure can't afford a big fast one! Sandisk 280 mb/s 32gb is $125 so that's actually not too bad. Might pick one up in a couple of months. Will post results.
     
  4. zathras

    zathras Mu-43 Regular

    161
    Jul 13, 2014
    Waikato, New Zealand
    Chris Nielsen
    I noticed something peculiar with the tests, the burst is full 90 mb/s however continuous mode is more like 30 mb/s. I did some research and it seems that is normal for sd cards.
     
  5. Growltiger

    Growltiger Mu-43 Top Veteran

    652
    Mar 26, 2014
    UK
    Another thing to watch out for is that you often see read speeds quoted, but what we care about are write speeds. So be sure to look up the write speed before buying. Some poor cards can read fast but write very slowly.

    My tests on my SanDisk Extreme 32GB and 128GB cards, both rated at 45MB/s, gave results of read=44 and write=43, which is excellent. (This was with a good quality USB3 card reader connected to dedicated USB3 hardware on an i7 processor. The test was continuous, using the entire card, not just a burst.)

    I have not tested the SanDisk Extreme Plus, but they claim read=80, write=60.

    The Sandisk Extreme Pro claims 95 and some are 280.

    Note that all these speeds are MB/s and not Mb/s. i.e. Bytes not bits.
     
  6. zathras

    zathras Mu-43 Regular

    161
    Jul 13, 2014
    Waikato, New Zealand
    Chris Nielsen
    As I found in my testing the 95 mb/s card gave me approx 90 mb/s so pretty much like it said on the tin. I found scary looking test results for other brands so sticking with sandisk
     
  7. Growltiger

    Growltiger Mu-43 Top Veteran

    652
    Mar 26, 2014
    UK
    I just tested my older Transcend 16GB cards. They are marked with a 6 in a circle which perhaps means class 6.
    Read=21.0MB/s
    Write=11.6MB/s
    It shows how write speeds can be much slower than read speeds, which is what get advertised.

    So my Sandisk Extreme cards, which is what I use now, have write speeds four times faster than my Transcend cards (44 vs 11).