SD Cards – Are All Things Created Equal

EyeFi-cardMemory card manufacturers are always touting the latest and greatest cards with ever increasing speeds, but does it really matter how much you spend on a card. To put this idea to the test, we took a handful of different cards and used CrystalDiskMark to test the read and write speeds of the different cards. Continue reading to see how low-budget generic cards stood up to the top brand name’s cards.

The Cards

The cards that were tested are all very affordable being SD cards and included:

The Testing

sandisk-cardThe testing was all done on an Alienware  i7 laptop using the built-in SD card reader. The software used was CrystalDiskMark. The test settings used the default of 5 tests at 1,000MB.  The sections below are as follows:

  • Seq : Sequential Read/Write Test (Block Size = 1024KB)
  • 512K : Random Read/Write Test (Block Size = 512KB)
  • 4K : Random Read/Write Test (Block Size = 4KB)
  • QD32 : Random Read/Write Test (Block Size = 4KB, Queue Depth = 32) for NCQ&AHCI

Test Results

Card Price SEQ
Kingston $16.98 23.27 14.52 22.29 0.544 3.351 0.113 2.464 0.072
Micro Center $14.99 21.90 10.47 21.85 1.758 8.283 0.018 8.697 0.020
Sandisk $18.99 23.66 23.02 23.09 1.541 5.239 1.490 4.538 0.473
Eye-Fi $99.99 12.10 11.75 11.99 1.705 5.095 1.372 5.813 1.702

Interpreting the numbers

Kingston-cardI was actually a little surprised at the numbers as I expected more consistency across the board. As you can see, difference cards performed differently, and sometimes drastically, from each other. Generally speaking, the Sandisk card will have the best overall performance for use in a camera….you would think.

To validate the data, I then used a MacBook Pro with Black Magic Disk Speed Test and redid all of the tests and got the following results:

Card Write Speed Read Speed
Kingston 15.3 MB/s 20.3 MB/s
Micro Center 7.7 MB/s 14.4 MB/s
Sandisk 12.9 MB/s 19.3 MB/s
Eye-Fi 8.4 MB/s 19.0 MB/s


Using the Black Magic Speed Test the Kingston reigned supreme with the Sandisk coming in a close second. The Micro Center generic card came out on the bottom and the expensive Eye-Fi card had really bad write speeds but quite fast read speeds.

What does this tell you, it tells you not all cards are created equal and often times you do get what you pay for as higher end cards generally have better performance than lower end budget cards


Kerry Garrison lives in Castle Rock, Colorado with his wife and two dogs. With 10 years of experience shooting products and 5 years of experience in the wedding industry, Kerry brings a good deal of technical know-how and can explain topics in easy-to-understand terms.

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3 Responses

  1. Ken says:

    thanks for the test,
    by the way, i use buy the kingston and sandisk both in the past, and skipped kingston for the reason they started to show card error on the camera while shooting a few times, (CF cards) on my canon slrs, and those cards had more problems with my nikon dslr.
    now i buyy either the lexar or´s worth the price you pay.

  2. stuartchard says:

    Its worth noting that some cards such as the sandisk and Transcend come with lifetime warranty. Just register yur card on their respective web sites. This will also valdate that the card is genuine product and not a fake.

    stuart chard

  3. brandon cruz says:

    Thanks for thorough testing Kerry!
    So I wonder how Sandisk can rate their cards at 45mb/s?
    One other point that is also important is the quality of the SD cards plastic shell's as they are definitely not built to the same specs. I have an Eye-Fi 4gb and few Patriot class 10 cards and they all have developed splits or crack quite quickly. The few Sandisk SD's that i've collected over the years seem to hold up better and the shells feel more solid.

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