I needed a fast, reasonably priced, high capacity Micro SDXC card for a review I’m working on (which we’ll get to next week hopefully,) so I turned to Amazon a couple of weeks back and got a Samsung 64GB EVO Class 10 Micro SDXC card.

Samsung 64GB EVO Class 10 micro SDXCI’ll admit, the selling point of this over the next card that was a buck or two cheaper was that it had the word EVO on it. I am that sentimental about that old phone.

We’ve had a few requests to benchmark these cards both in and out of a phone. This is going to be my first attempt at this and I’ll lay out the benchmarking steps taken here so if anyone sees anything I’m doing wrong, feel free to chime in.

Testing methodology

Doing this on two sides – a phone side, and a computer side.

On the computer side, I am using CrystalDiskMark 3.0.3 64 bit, Windows 7, nothing running that’s on the IO channel, a Kingston MobileLite USB 3 card reader, an Anker Upspeed USB 3.0 adapter that’s topped out at 102 MB/S on a drive that writes at 102 MB/S sequential (meaning I think it’s doing its job.)

CrystalDiskMark is set to nine passes at 4000MB so that should average out any inconsistencies.

On the phone side I’ll use my HTC One M8 and A1 SD Bench. I’ll point out here that the phone side had the most variation between testing and phone models (IE the EVO did better on some, worse on other tests.) As such I’m going to say since the ROM, hardware, kernel, etc vary significantly and as such I’m inclined to give the top sustained a bit more credibility.

I’ll leave the SD formatting to however the card shipped unless anyone’s particularly concerned with the exFAT vs FAT32 performance changes.

Results (computer)

Samsung 64GB EVO Class 10 Micro SDXCAfter a couple of tests (and an hour+ of testing,) in which the numbers varied only in the read MB/s being .01 lower the CrystalDiskMark numbers are as follow:


  • 46.59 sequential
  • 29.12 512K
  • 7.563 4K
  • 8.095 4K QD32


  • 22.86 sequential
  • 11.28 512K
  • 0.039 4K
  • .0.32 4K QD32

Results (phones)

  • Read 43.98MB/SA1 SD bench test
  • Write 23.33MB/s

What it claims to be able to do

Up to 48 MB/s. On the computer it got within 3% of achieving that, and my test does not account for exFAT overhead, so I’ll buy 48 MB/s read rates. No test achieved that in write rates however coming in at about 60% of the maximum rate.

Wrap up

At 94.4% the read speed and 80% the write speed with substantial variation from test to test the phone tests (others than A1 SD also,) appear to give me an approximate feeling of what the thing can do, so the phone tests are useful and I’ll continue them.

Does what it’s supposed to, middle of the road pricing, has the name EVO, comes with an SD adapter. I’d say a slightly above average card for the money.

The Samsung 64GB EVO Class 10 Micro SDXC is available from Amazon for $32.78, or other retailers on Amazon link for ~$24