This morning, SanDisk announced its newest line of microSDXC cards, the Extreme series. And they're Extreme[ly] fast. But as you and I know, manufacturer speed claims for microSD cards aren't exactly indicative of real-world performance figures (especially in smartphones), so we actually compared SanDisks's new Extreme cards to the older Ultra series. Here's what we found.

On Android, we used the A1 SD Bench app loaded on a Galaxy Note II to compare performance between a 64GB Extreme SDXC and an older (used) 64GB Ultra SDXC.

The thing to note here is that the Note II we used to test these cards does not support UHS-1, and will get what SD card manufacturers refer to as "Class 10" performance. Most smartphones and tablets do not support UHS-1 speeds, and thus will not be able to get anywhere near the claimed maximum performance of UHS-1 microSD cards. One notable exception is the Exynos Octa version of the Samsung Galaxy S4 (model GT-I9500). Still, there is great disparity in the performance of Class 10 microSD cards, and the Extreme SDXC is the quickest I've ever seen.

Sandisk Extreme 64GB A1 1 Sandisk Ultra 64GB A1 2

I'm guessing those don't need labels, but just in case you're feeling particularly incredulous, the result on the left is the new Extreme card, while the result on the right is the Ultra card. The Extreme card was over twice as fast in the write test, and more than 50% quicker on read.

If you want proof that UHS-1 support makes a big difference, the Windows-based test (using CrystalDiskMark) produced a much more staggering disparity between the two cards. Check it out.

Sandisk Extreme 64GB CDM 1 Sandisk Ultra 64GB CDM 1

The new Extreme card nearly doubles the Ultra for read speeds, but the write performance is what really stands out: the Extreme benchmarks almost five times faster than the old Ultra. That's pretty crazy. These results, as compared to the ones benchmarked in Android, also line up more with SanDisk's claimed performance figures of "up to 80MB/sec read and up to 50MB/sec write."

The new Extreme cards are available in capacities ranging from 16GB (SDHC, max write 30MB/sec, $59.99) to the 64GB SDXC card we tested here ($199). You can check them out SanDisk's website, here, and they should be available at major online retailers in the coming weeks.


David Ruddock
David's phone is whatever is currently sitting on his desk. He is an avid writer, and enjoys playing devil's advocate in editorials, and reviewing the latest phones and gadgets. He also doesn't usually write such boring sentences.

  • Elias

    4K recording, anyone?

  • peter

    What i really want to see is a 128gb micro SD card..heard that it may be announced later this month..fingers crossed

  • fanSte

    I've got a Galaxy Note II too, but I can't get my 64GB SDXC UHS-1 card to work. How did you manage that?

    I got the message "Blank SD card"

    • http://www.androidpolice.com/ David Ruddock

      You may need to try a different formatting method. Try NTFS.

      • fanSte

        Tried that too

      • antifud

        NTFS isn't actually implemented well on android (or anything else aside from windows, for that matter). Try exFAT/EXT3/EXT4.

        • EH101
          • Nomaan

            Can we use paragon on other phone which does not support exfat natively? I mean my phone is expandable upto 32gb but 64gb works in it without issues when formatted to fat32. Currently my fat32 formatted 64GB gives read/write speeds similar to class 4. Will it give class 10 speed since its a class 10 card?

          • EH101

            Yes, as long as you have root and Paragon itself works on your device, any Android phone can work with ntfs. I believe it can also be set to auto mount on boot as well.

        • http://www.androidpolice.com/ Artem Russakovskii

          exFAT is the way to go for best cross-platform compatibility.

    • thor2001

      Use your Note2 to format the card.

      Formatting the card in my pc killed my first card...


      • fanSte

        Got the message after formatting card in my Note2.

        And what do you mean by your pc killed your first card? You can trow it away after formatting the card in the pc?

    • EH101

      You might just have a bad card. If it's within return period, try getting it replaced. Also, try it in another device first if possible.

    • rahlquist

      SDXC is supposed to be formated EXFAT http://www.lexar.com/support/sdxc-faqs

    • http://www.androidpolice.com/ Artem Russakovskii

      I didn't have to format the card the way it came, but I just checked for you, and it's formatted exFAT.

    • drksilenc

      are you rommed? if so then its a kernel issue.

  • HopelesslyFaithful

    finally a place that is reputable with 4k tests. Still wish 4k was better but it at least doesn't suck. though the price is ridiculous.

    EDIT: also when will phones actually support UHS-1.....i have not seen a phone labeled to support it yet so this makes it still useless....i hope i am wrong so please post any phone that supports this (especially on the sprint network)

    • MasterMuffin

      Not on Sprint, but as the article says GT-I9500 :)

      • HopelesslyFaithful

        thanks..i honestly don't understand why it is taking forever to support UHS-1...it ahs been around a long time. Most laptops and cameras don't support it either. I was pissed to find out that my RX-100 does not even support it....is it really that hard to support come on!

        Anyways, thanks for the response +1

    • Vitaly

      Yeah the price really sucks but since they have no competitors why should they sell it at a lower price?

  • Ricardo Kummel

    What about testing these cards on an Asus Transformer Infinity??

    • MasterMuffin

      It doesn't matter what you test these on, the extreme is faster

      • Michael Pahl

        test these on the iPhone 5!....waaaaiiitt....

        • MasterMuffin

          I did it! There's only one big enough hole in it, I put it there and now my phone isn't booting. Hjelp??? :D

          • Vitaly

            Have you tried to turn it off and on again? :D

          • squiddy20

            "You're holding it wrong."

          • MasterMuffin

            I did but @squiddy20 his comment helped, I held it from the top with my fingers and it dropped under a train. Problemo solved!

      • Ricardo Kummel

        I just wonder if those cards would be recognized by the TF700, nothing else. ;)

        I know that some ~UHS 1~ do work but that a hit or miss with the same brand/class (64gb - probably because Asus vows up to 32gb only).

        • Nomaan

          IMHO, yes they should work, atleast the ultra when formatted to fat32 which makes it slower I guess just like class 4. I have 64GB ultra and i have tested it on Galaxy s2,s3,evo3d,xperia ray,play and so many other tablets and phones, it works on all of them without issues. If you want the additional storage and similar speeds as your 32gb card then I guess you should go for it.

  • TY

    How does this compare to flash storage in phones? Now we know the reason why 16GB more in a phone can cost at least $50, huh? Stop that "OMG WHY DOES 16GB COST SO MUCH MORE THAN AN SD CARD BLAHBLAHBLAH"

    • Matthew Fry

      Yeah... except that my internal SD rates at about the same as ultra SDXC which costs... $14 dollars on Amazon. Retail. That means it has to be manufactured, printed on, packaged, shipped and shipped again. Based on that, I'm guessing the 16GB more in the phone costs... 9 dollars.

      • Freak4Dell

        Don't forget the bulk discounts.

  • ithehappy

    Great, but no thanks, 200 bucks! will give me a 2 TB Black HDD!

  • http://www.androidpolice.com/ Artem Russakovskii

    That's where they start, then prices (hopefully) quickly drop to more manageable levels.

    • AcemanX AcemanX

      theyre 97 now

  • Angus

    The ultra would probably give better results if it wasn't half full. o_0

    • Saiful Zaree Johar

      Eh? All I can see both cards are pretty empty, with total and free space avvailable the same

      • Darshan Karia

        He is talking about CrystalDiskMark second image... But, then again, it may not make that much of difference IMHO...

  • Gadget-Man

    My Lexar micro sd card for my samsung galaxy s3 is fast

  • http://notionage.com/ SEO Singapore

    Is this Extreme SDXC 64G can fully support new Samsung Note 3?

  • http://notionage.com/ SEO Singapore

    May I know is this Extreme SDXC 64g is fully compatible with new Samsung Note 3? I intend to buy for use on my note 3.