Compact Flash and Secure Digital Cards – The Cost of Being at the Cutting Edge

I had to order some new Compact Flash (CF) and Secure Digital (SD) memory cards for my Iceland trip a day or so ago and I was struck by what it costs these days to be at the cutting edge of memory card technology. By way of introduction and example: A 32 Gigabyte Compact Flash card with a write capability of 90 MB/s costs in the order of $450+ Australian dollars; yet a 32 Gigabyte Compact Flash card with a 60 MB/s write speed only costs around $230 Australian. Thats a difference of more than $200 for the same size card but with a write speed one third slower. The immediate and obvious question is – Does that extra speed make a difference? And is it worth the price of admission?

From my point of view as a contemplative Landscape, Nature and Wilderness Photographer the answer to both questions is a resounding ‘NO’. My reasons are fairly straight forward and it has a lot to do with how I choose to set-up my camera. You see, my Canon 1DSMKIII is capable of taking both CF and SD cards and writing to both cards simultaneously. This is a great feature as it means I can load a 16 Gigabyte CF and 16 Gigabyte SD card into the camera at the same time and set the camera to record the RAW file to both cards at the same time – effectively giving me a RAID1 array for data redundancy in my camera. What this means in layman’s terms is if one card goes bad I still have the other card with exactly the same RAW images on it – An excellent in the field back up. The only downside of this set-up is it effectively halves the number of frames one can take without changing cards – but since memory is now so cheap this really isn’t an issue. The only other problem with loading both CF and SD cards and writing to both simultaneously is that you are then limited by whatever card has the slowest write speed to clear the cameras internal memory buffer. There is no point having a CF card capable of writing at 90 MB/s if the matching SD card that the camera is simultaneously writing to writes no faster than 30 MB/s. The CF card will clear the camera buffer faster than the SD card but you still wont be able to shoot again until the camera has finished clearing its buffer by writing the same files to the slower SD card. So that extra speed and cost is wasted. Thus in this example if the fastest SD card one can buy writes at 30 MB/s there is no point buying CF cards that write any faster than 30 MB/s. A 32 Gigabyte CF card with a write speed of 30 MB/s only costs about $100 – A whopping saving of $350 over the 90 MB/s write speed card! For the same capacity!

So, if I don’t need cards capable of writing at 90 MB/s a second who does?

There are numerous applications where it might be beneficial to have CF cards capable of these kind of blistering write speeds. A motor-sport photographer shooting with a Canon 1DMKIV in motor drive at ten frames per second has a good practical use for this kind of card speed. It is arguable that someone shooting with a 60 megapixel Phase One Medium Format Digital Back might also have an application for this type of card. The slower paced Landscape, Nature and Wilderness photographer like myself doesn’t need this kind of write capability and for a change can pocket the savings (us landscape photographers don’t often get this kind of win!).

So what did I order?

For my Iceland trip I ordered (in addition to the cards I already have) two Sandisk 16 Gigabyte 30 MB/s CF cards and two Sandisk 16 Gigabyte 30 MB/s SD cards – total cost $395.80. If I had ordered the same sized cards but with a 90 MB’s write speed I would have paid an additional $330 just for the CF cards (Sandisk currently dont make SD cards with write speeds faster than 30 MB/s) and effectively wasted my money by being unable to take advantage of that extra speed because of my set-up to shoot to both cards simultaneously. It is perhaps fair to say I have traded some speed for data protection – but that is a compromise I am prepared to make every-time.

2 thoughts on “Compact Flash and Secure Digital Cards – The Cost of Being at the Cutting Edge

  1. I’ve recently started a blog, the information you provide on this site has helped me tremendously. Thank you for all of your time & work.


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