Dumb question of the week: Why do CF cards cost more than SD cards?

by philg

I’m getting ready for a trip to Israel and Jordan so it is time to buy a memory card. My Canon digital camera takes either CF cards or SD cards. It seems to write and read much faster with the CF cards so that would be the natural choice except that 128 GB CF cards at Amazon are $300-700 (name brands; I don’t want to trust my images to “Komputer Bay”) while 128 GB SD cards at Amazon are $96-$136. What’s different about the innards? I don’t think it is the package that makes a CF card expensive because an 8 GB CF card sells for as little as $15.

[Separately we get to the question of why a 256 GB SSD costs $191 at Amazon but Dell charges $300 to upgrade a to-be-built laptop from a 128 GB drive to a 256 GB SSD. The mechanical hard disk market seems almost perfectly rational by contrast.]

13 thoughts on “Dumb question of the week: Why do CF cards cost more than SD cards?”

  1. > What’s different about the innards?

    The CF card implements a full IDE interface, runs a faster clock, uses more power, and has more than twice as many pins.

    I expect the real answer, though, is just that more people are currently buying SD cards (because they’re used by point and shoot cameras, cell phones, and laptops), so more of them are being made at once, so the price of them is lower. Same reason it’s currently cheaper to buy an SD card, which is NAND flash with a controller attached, than it is to buy the raw NAND part directly.

    (It’s preferable to buy bare NAND if you don’t trust the wear-leveling algorithms that are abstracting the flash chip into a standard block device, and you want to manage the flash blocks yourself instead.)

  2. I assume it is because people who buy cameras that use CF cards are less cost sensitive than those who buy cameras with SD (with odd exceptions to the rule like the 5D III that takes both).

  3. Economies of scale. Way more cameras that take SD cards are made = more SD cards. Only the higher end cameras take CF these days. Canon must sell a gabillion more Rebels than 5D Mark 3s.

  4. I eagerly await an answer from those who know more than me as I too have wondered this same point about the CF SD divide. My guess is that heaps of cameras take SD cards but only professional level (or more expensive…) cameras now call for CF cards and so it comes down to an economies of scale issue.

  5. My guess: CF cards have largely fallen out of use, since SD cards are much smaller but offer similar capacities.
    So it’s probably a combination of economies of scale (SDs have larger production volume, hence lower costs) and price discrimination (CF cards are pretty much exclusively used in DSLRs, i.e. expensive cameras use by proessionals, so somebody who uses CF cards can be expected to be willing to spend more on photography hardware)

  6. I don’t have an answer, but a suggestion: if you don’t run into buffering problems (which you probably won’t if you’re not shooting sports or wildlife or otherwise holding down the shutter at 6fps for several seconds), just use a cheap and huge SD card. If you do buffer, use a fast (expensive) CF card as your default, and keep a cheap and huge SD card in the camera for times when you fill up your CF card.

    If you’re using the 5D3 and run into buffering problems, get a CF card with UDMA7 (the fastest standard it supports). That increased my continuous raw shots before buffering (with high speed continuous) from 13 to about 31, and then increased the frame rate once buffering started. Made a huge difference with flying birds and sports.

  7. Folks who say it is economies of scale: That doesn’t explain how lower capacity CF cards are available for $15-30. If it were truly a boutique industry with Swiss elves tweezering the chips into the package then I would expect the minimum price of a CF card to be $100+.

    Folks (e.g., Peter) who say it is because people who own expensive cameras don’t mind paying 2X: That is equivalent to saying “traditional market economics are suspended for this product and suppliers can charge whatever they want”. Why wouldn’t the price then be $1000 for a CF card? If I have two $7000 professional bodies, surely that is an insignificant extra cost. (Given that recent European Union bust of the companies that had a CRT cartel going for 20 years, I am a little more inclined to believe that there may be a cartel in CF cards that keeps the price high enough for killer profits but low enough that people don’t simply switch to bodies that use SD cards.)

    Chris: Since you seem to be the only person who actually knows something about CF or SD cards… how much higher is the practical throughput for a reasonably good CF card compared to a reasonably good SD card?

  8. > Folks who say it is economies of scale: That doesn’t explain how lower capacity CF cards are available for $15-30.

    I still buy the economies of scale argument; large CF cards are only used by professional cameras, whereas large SD cards are used in many different kinds of devices.

    > Chris: Since you seem to be the only person who actually knows something about CF or SD cards… how much higher is the practical throughput for a reasonably good CF card compared to a reasonably good SD card?

    http://www.robgalbraith.com/bins/camera_wb_multi_page.asp?cid=6007-12452&sort_col=jpeg&sort_dir=DESC has measurements on the 5d3 — 80MB/s RAW for the fastest CF vs. 20MB/s RAW for the fastest SD. Even a reasonably good CF will get 40MB/s.

    This is compounded by the 5d3 not supporting the UHS-I standard, which would give you 80MB/s. So buying an expensive SD card for the 5d3 doesn’t gain you anything past a cheap Class 10 card.

    (The fact that UHS-I and UHS-II now exist, even though the cards have been rare up to now, means the CF is on the way out. It just took SD a long time to get the high clock/transfer rates.)

  9. philg: “That doesn’t explain how lower capacity CF cards are available for $15-30.”

    Looking at one manufacterer that doesn’t appear to be true.

    Lexar Professional 400x 128GB SDXC UHS-I r:60MB/s, w:20MB/s $125 (this price seems oddly low)
    Lexar 128 GB SDXC 128GB SDXC 20mb/s -> $167
    Lexar Professional 800x 128GB CF r:120mb/s, w:? -> $308
    Lexar Professional 1000x 16GB CF r:150MB/s, w:? -> $77
    Lexar 32 GB 400x 32GB CF r:60MB/s, wL? $89

    The speed of the CF is much higher. Faster things typically cost more. Faster things with more memory cost more.

    If they are “the same”, buy the cheaper SD card.

  11. CF is Professional Level cameras.
    SD is consumer level.
    $15 CF is discontinued items/counterfeits.

    XQD is the replacement of CF which 18 year old standard.

  13. Thanks, Joseph. One of the luxuries of being a helicopter instructor is that I don’t worry about my personal safety when I am flying on a commercial airline, visiting a country that is in the news, etc.

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