Best Memory Card For The Galaxy S8 & S8+

Best Memory Cards Galaxy S8, S8+

A speed test comparing all the most popular UHS-II and UHS-I memory cards in the Galaxy S8 and S8+ Phone.

Use this guide to find the best memory card for your needs.


Phone Camera Specs

Processor: Octa-Core Chipset

Memory Cards: UHS-I Single Slot

Rear Camera Front Camera
Sensor: 12MP 1/2.5″ Sensor: 8Mp 1/2.5″
Lens: f1.7 Lens: f1.7
Image Stabilization: Optical
Video: 3840 x 2160p 60 fps
35mm-Equivalent Focal Length: 26  —


Samsung Galaxy S8, S8+ – AmazonBHphoto



Best Memory Cards For The Samsung Galaxy S8 & S8+ Phone

Unlike a lot of other sites that list memory cards for the Galaxy S8, I actually own and test them all.


There is a lot of confusion when it comes to testing SD memory cards in the Galaxy S8. Most of the benchmark software will test the emulated SD memory card which is not the real external memory card.

A1 SD allows you to test the real SD memory card. Many of the other programs will allow you to browse to find the external memory card in /storage/0000-0000 but I was then getting “access denied.” So A1 SD was my application of choice for doing these test.


Samsung Galaxy S8 Memory Card Speed Comparison

Memory card read / write speeds were tested using A1 SD in the Samsung Galaxy S8+ using the Long – Default test with the fastest results taken out of several tests.

Micro SD Memory Card Read Speeds Write Speeds Order
UHS-II – phone not capable      
Sandisk Extreme Pro 64GB UHS-II untested  untested Amazon
Lexar 1800x 64GB UHS-II untested  untested Amazon
Lexar 1000x 64GB UHS-II 70.88 MB/s 35.19 MB/s Amazon
Delkin 64GB UHS-II untested  untested Amazon
Sandisk Extreme Pro 64GB U3 72.23 MB/s 68.48 MB/s Amazon
Sandisk Extreme Plus 64GB U3 73.25 MB/s 66.67 MB/s Amazon
Sandisk Extreme 64GB U3 78.13 MB/s 56.89 MB/s Amazon
Sandisk Ultra C10 – Old Version U1 38.79 MB/s 15.80 MB/s don’t buy
Sandisk Ultra C10 – New Version 70.55 MB/s 31.40 MB/s Amazon
Lexar 633x 64GB U1 67.46 MB/s 23.54 MB/s Amazon
Lexar 300x 64GB U1 36.98 MB/s 22.64 MB/s Amazon
Transcend Ultimate 633x 64GB U3 65.67 MB/s 39.65 MB/s Amazon
Transcend Premium 400x 64GB U1 64.75 MB/s 22.87 MB/s Amazon
Transcend Premium 300x 64GB U1 65.53 MB/s 23.41 MB/s Amazon
Transcend High Endurance 20.21 MB/s 20.44 MB/s Amazon
PNY Pro Elite 64GB U3 65.15 MB/s 64.60 MB/s Amazon
PNY Elite U1 66.11 MB/s 28.69 MB/s Amazon
Samsung Pro+ 64GB U3 66.10 MB/s 68.37 MB/s Amazon
Samsung Pro 64GB U3 66.99 MB/s 62.67 MB/s Amazon
Samsung Pro Select 64GB U3 67.56 MB/s 68.47 MB/s Amazon
Samsung Evo 64GB U3 15.16 MB/s 20.17 MB/s
Samsung Evo Select 64GB U3 15.02 MB/s 18.42 MB/s
Samsung Evo+ 64GB U1 63.92 MB/s 19.35 MB/s Amazon
Samsung Evo Select 64GB U1 67.26 MB/s 20.62 MB/s Amazon
Samsung Evo 64GB U1 37.48 MB/s 20.62 MB/s Amazon
Delkin 64GB 65.44 MB/s 64.78 MB/s
Patriot 64GB U1 53.42 MB/s 19.50 MB/s Amazon
Netac Pro 64GB U3 62.48 MB/s 32.39 MB/s Amazon 

I recently tested the Samsung Evo and Evo+ U3 cards and for whatever reason I could not get them to read with any sort of decent speeds. Tried it on two different phones with no luck. Maybe these cards just suck or came from a bad batch?

On my computer I get Reads of around 88MB/s and Writes around 60MB/s. So I don’t think it’s the card. However when I test other cards in this phone they perform fine. Just these two cards are not liked. I’ll wait for a software update and try again.


Top 3 Fastest Write Speeds

(Tested in-camera)


Top 3 Fastest Cards Read Speed

(Tested in-camera)

  • Sandisk Extreme Pro – Amazon
  • Sandisk Extreme Plus – Amazon
  • Sandisk Extreme – Amazon



Memory Cards & Brands To Consider Avoiding

The only cards that I would be cautious about would be any old cards, like the Sandisk Ultra – Old Version. That card ran very hot and its performance when testing was all over the place. In fact, avoid old versions of any card on Amazon. I think some have been labeled old even since I’ve purchased these so I’ll try to update as much as I can.

There is also Patriot and Netac Pro. I don’t know much about these brands so I wouldn’t trust them either. I actually gave one to my niece for her to use in her tablet, so I’ll know soon if there are any problems with them.



Memory Cards & Brands You Can Trust

The best all around brand seems to be Sandisk. However, Lexar, Transcend and Samsung are also great. It’s not uncommon for the cards made by Samsung to work best in Samsung devices. That’s the way Sony cards typically work. They may not be the fastest, but they usually are the most reliable.



Frequently Asked Questions


Will The Galaxy S8 Support 128GB and 256GB Cards?

Yes. The Galaxy S8 and S8+ support micro SD memory cards up to 256GB.


Does The Galaxy S8 / S8+ Support UHS-II Memory Cards?


While USH-II memory cards do work in camera, I see no speed improvements over standard UHS-I cards.


My Memory Card Is Slow Or Isn’t Working

There are a lot of counterfeit cards out there especially on Ebay, so make sure you buy your cards from a trusted source. If you buy on Amazon, buy from the manufacturer directly.

Sometimes cards can just be bad. It happens. Send it back for a replacement, or send it in for a warranty.

Be sure the card is clean and the connectors inside the phone are clean.



Best MicroSD Memory Card For The Galaxy S8 / S8+ | Bottom Line

There are a lot of cards out there made by a lot of different brands. Some better than others. A lot of the top brands like Sandisk make the fastest cards, but also the most reliable. If you’re using your phone to access your SD card a lot (like installing games on it), then it may be useful to buy one of these faster cards.

If you’re just looking for a card that you can use for storing extra photos or video on, then there may be no need to break the bank, depending on your needs.

  • Fin T.

    Have you tested the uhs-ii cards with the galaxy s8?

  • Not yet, still waiting on getting the phone.

  • Fin T.

    Bummer. I’ve had mine since 4/19… got the SanDisk uhs-ii card, but unsure if it’s being fully utilized. What benchmark can i run?

  • Couple things you could try, A1 SD or SD Tools. You can also see if the card slot on the phone has the extra set of teeth that match with the UHS-II cards.

    Samsung with their NX1 camera shipped with UHS-II hardware, but it wasn’t until later that they released firmware to take advantage of it. So if the hardware is there and you see there are extra teeth, there could be hope that firmware offers UHS-II later if you see it underperforming right now.

    Let me know if you get UHS-II speeds or not so I can update. I won’t be able to test likely until this weekend or later. Just too much stuff on my plate right now.

  • Fin T.
  • Fin T.
  • Run the A1 SD benchmark a few times. There is something about that software caching the results so you need to run it a few times to get the most accurate results. PCMark seems like it’s not displaying accurate results. Based on A1 SD it looks like the phone is not utilizing UHS-II. You could also try SD Tools to confirm.

  • Actually it might UHS-II, The Red card on A1 SD use to be internal and the yellow was external. But if that’s the case, the internal memory seems like it’s very slow. So something seems off.

  • There are a few ways to test memory card speeds and there aren’t a lot of great options for Android.

    So Sequential means that data is written in order and read in order. 1,2,3,4,5,6 etc.

    Random would be if data was fragmented all over the card so it would read or write 1,6,3,5,4 etc. This slows things down a lot.

    I think some of the results might be testing the sim card, or maybe the internal memory is divided up.

  • JimBob_SF

    Alik: Bravo for being the only place Google could find with relevant information on the S8 and whether it is UHS-II compliant. I’ve been searching for a month, talked with Samsung reps… nobody knows. I posted this blog link in an XDA thread so others can follow your testing. Thank you from many!

  • WhippetNYC

    Hello Alik, I posted a comment earlier this morning but it’s no longer there. May I ask if you might be so kind as to see what might have happened? My comment ought not have been controversial, as it’s mostly technical vis-a-vis types of Micro SD cards, etc. Thank you.

  • Hey WhippetNYC, your previous post included a link so it was awaiting moderation. I wasn’t able to check comments yesterday. I approve every comment that’s not spam.

    In answer to your question, the speed tests were done in windows 10. I don’t have the S8 because I’m ordering it from BHphoto as an unlocked version since I don’t plan to keep it and they don’t have any available until early May. I’ve been trying to find anyone else that has the phone but nobody I know has it so I can’t test the cards until they are in stock. It’s very frustrating.

    And thanks for the feedback on Samsung cards. There are so many different model numbers that do different things, I’ll try to clarify which card exactly I have based on model number on my next update.

    I’m still trying to see if I can get the phone sooner. But let me know if there is anything else you want to see when I do the tests in-phone. Maybe I’ll just walk into Verizon this weekend and get one cash.

  • WhippetNYC

    Hi Alik, thanks for your reply. May I ask if I should repost that “lost post” or might you moderate/post it after reading it please? Thanks.

  • I approved it. It went through.

  • Stephen Amos


  • Ben Hermagerd

    Alik, I just picked up a SanDisk Ultra UHS-I Premium edition 200Gb C10 card for my S8+. How can I tell if it’s the old version (marked Don’t Buy) or the new version. Thank you,

  • The old version has this serial: SDSDQUAN-064G-G4A Also, the new version is made in China. I think the old version was made in Malaysia, I’m out of town so I can’t confirm for sure.

    See on your packaging where the card was made. If it’s made in China I think you’re good to go.