High-speed SDHC card speed comparison

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Since I ordered my Olympus E-M1II, I’ve felt the need to buy new SD memory cards as well, just to keep up with the data rates it can produce.  But of course, cards’ labeled speeds aren’t necessarily all that accurate (“your mileage may vary,” as car ads used to say), so I took advantage of discounts and gift certificates to pick up one each of four name-brand cards, and tested their read / write speeds.  What’s common among them:

  • 32 GB capacity
  • UHS-II / U-3 ratings
  • Fastest SDHC card for their brand

For comparison, I also included one card that until recently *was* the fastest memory card I owned.  So here are the contenders, in no particular order, with their current price at Amazon (just because Amazon sells all of them, so this keeps pricing somewhat consistent between them):

  • Lexar Professional 1000x — advertised speed 150 MB/s (read), available at Amazon for $22.48.  My “old standby.”
  • Lexar Professional 2000x — advertised speed 300 MB/s (read), $54.95 at Amazon
  • Delkin UHS-II — advertised speeds 250 MB/s (write) / 280 MB/s (read), $53.90 at Amazon
  • Transcend — advertised speeds 180 MB/s (write) / 285 MB/s (read), $44.99 at Amazon
  • SanDisk Extreme PRO — advertised speed 280 MB/s (read), $57.69 at Amazon

Lacking a solid, repeatable way to speed test the cards in my camera itself, I used two USB 3.0 card readers — a Kingston MobileLite G4, and a Lexar reader that came with the “2000x” SDHC card — connected to my iMac, and running Blackmagic Disk Speed Test.  I recorded the peak sustained write and read speeds, and for good measure, also calculated the “best case” (using the faster of the two values for each card) write speed per cost.  Here are the results I had:

SDHC speed comparison table

General conclusions

  • Actual and advertised card speeds tend to be pretty far apart — no real surprise here.
  • In most cases the “free with the card” Lexar reader was as fast, or considerably faster than the Kingston reader (that I purchased, some months back).  Writing to the SanDisk card was the notable exception to this, I don’t really know why.
  • I didn’t really expect much from the Lexar 1000x — it’s an older / slower model, and the numbers support that — so it’ll get demoted to serve in my E-M5II, which is less-demanding (no 4K video, no Pro Capture mode) than the E-M1II.
  • Both the Lexar Pro 2000x and Delkin cards are stand-outs — both in terms of raw speed, and in terms of value (speed per cost).  They both work without issue in my E-M1II (this may not be the case with larger capacity versions of the same cards, if online reports are to be believed), and I highly recommend either of them for your use.
  • The Transcend card is $10 cheaper but considerably slower than the Lexar Pro 2000x and Delkin cards — it’ll work for you, but I can’t recommend it as a good value.
  • The SanDisk card is good enough for everyday use, but is expensive for what you get — it will definitely be pulling reserve duty in my camera bag, and I won’t be buying any more of them.