If you use a smartphone, then in all probability you are not a stranger to microSD cards. SD is an abbreviation of the term “Secure

MicroSD Card Buying Guide

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If you use a smartphone, then in all probability you are not a stranger to microSD cards. SD is an abbreviation of the term “Secure Digital”. At the moment, microSD cards used to be the smallest commercially available memory cards for a long time, but nanoSD cards have been introduced now. Our microSD card buying guide shows you what to look out for when buying your microSD card.

Different Types of Memory Cards

There are different sizes of memory cards, including:

  • Standard SD card;
  • MiniSD card;
  • MicroSD card: this is currently the most popular size of memory cards, and what this article is about.
  • NanoSD card: this was introduced by Huawei in late 2018. Huawei Mate 20 and Mate 20 Pro are the first smartphones to support this size of cards.

This is what a microSD card looks like:

sandisk 400GB microSD card

Why you should pay attention to that MicroSD Card

Despite their tiny size, microSD cards do pack a wallop, with 8GB and 16GB cards being available. Cards with smaller disk space are available too – 512MB, 1GB, 2GB, and 4GB. But unknown to lots of people, these cards are not only about disk size. Perhaps you have seen different retailers offer cards of the same disk size at significantly different costs, and naturally just went for the cheaper option?

Well, you might be shooting yourself in the foot. You see, microSD cards are rated by class. As such, you can have two 4GB cards with two different ratings, and one will perform better than the other. In some cases, some smartphones’ performances are impacted if you use a lower rated microSD card than it requires.

This are the reasons why you will find this microSD card buying guide useful.

MicroSD Card Buying Guide: Ratings

  • Class 2 -speed of 2 MB/s or higher is guaranteed at the best fragmented state where no memory unit is occupied
  • Class 4 – speed of 4 MB/s or higher is guaranteed at the best fragmented state where no memory unit is occupied
  • Class 6 – speed of 6 MB/s or higher is guaranteed at the best fragmented state where no memory unit is occupied
  • Class 10 – speed of 10 MB/s or higher is guaranteed at the best fragmented state where no memory unit is occupied

MicroSD Card buying guide: rating

For example, if you have a smartphone that does full HD video recording, you are better off with a card rated Class 4 or above.

Be sure that you know what the requirements of the device that you will be using a microSD card with, and check the card for a rating before buying. For many of today’s smartphones, I recommend that you do not use a card rated below Class 4. Not worth it.

Take a look at the close-up picture above. See the circled figure that the red arrow points to? That’s the rating of that card. That card is a Class 4 card. Not all manufacturers provide this information on their cards. Of course, if they don’t, you have no way of knowing.

As a rule, purchase microSD cards made by reputable manufacturers. One well known brand is SanDisk. Another is Kingston. If possible, avoid nameless cards.

MicroSD Card Buying Guide: Size/Capacity

What size of memory should you buy – 16 GB, 32 GB, 64 GB? It depends on your phone. Phones have maximum card capacities they can handle, so you need to look at the specs of your phone and then buy the largest capacity you can afford.

In 2015, SanDisk introduced the world’s first 200 GB microSD card. The same brand came up with the first 400 GB microSD card in 2017, and 1 TB cards are already on the way, as announced in February 2019 by Micron.

SanDisk UltraPLUS micro SDXC 200GB

MicroSD Card Buying Guide: Conclusion

Why should you care? Because it matters. Some of the complaints about some smartphones freezing up or hanging stem from the user putting in lower rated cards. Because the device requires something faster, each time info is to be accessed or lodged in the card, the device stutters, freezes or slows down significantly.

Video recording and/or viewing is another case, especially high definition video. Higher rated cards guarantee you good quality recording and smoother playback.

Now you know. If you found this microSD card buying guide useful, do share it with others. Happy shopping.

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  1. Thank you for this write-up.

    I have had issues with fake memory cards, flash drives, and external hard disks in the past, wasting quite a bit of money on them.

    In 2008, I decided never to buy a new memory device because it came cheap. Since then, I have always insisted on SanDisk memory cards. In November, when I wanted a 16GB mem card for my Samsung Wave, I waited until a friend was returning from USA so he could buy an original SanDisk card. I have filled it up with all sorts of files since then, and it has always performed well.

    I was unaware about this “Class” rating, though. Just checked my 2 SanDisk mem cards. The 4GB is Class 4, but the 16GB is Class 2. Damn! Well, I now use it primarily to backup my Phones’ data, so no big deal.

  2. @Yomi, what do say of memory cards that came in the box and still gave problems. I experienced this with the E71.

  3. I will like to say that this is one of the best post I have read this year, not just on Mobility but everywhere. The post goes deep into something important that most people take for granted.

    On a lighter note,
    “If you use a smartphone, then in all probability you are not a stranger to microSD cards” Unless you have used only iPhones all your life.lol

    I just confirmed now that my 16GB micro SD card is class ‘2’. This is something I will pay more attention to when buy a memory card soon.

    Pls do you sell micro sd cards?

  4. Cosign bosun99uk, this post is easily the ‘most useful blog post of the year’, had me scratching my card out its slot to see what number was on it.

    My Nokia E63’s memory card came with the package, and interestingly it does not have any class number. But I have not noticed any serious memory card related issues. Although there was a time my phone would freeze, I chalked it up to some tacky applications, and uninstalling them seems to have fixed that.

  5. Never knew memory cards have ratings. Now i know!

    I remember reading somewhere months ago that using the wrong type of memory card with some WindowsPhone will actually DAMAGE the card PERNANENTLY!. In addition to slowing down the OS.

    Have a look @ Windows Phone Locks-in MicroSD Cards

    I wonder what is so different in WindowsPhone (from other phones) that causes this o!

    I have never used a WindowsPhone, and am not planning on acquiring any – anytime soon. So I just filed the information somewhere on my own ORIGINAL, indestructible natural MEMORY – my BRAIN!

    Thank you for this info!

  6. Thanks for this valuable info Yomi.
    Never knew these things have class ratings. No wonder i was having hanging and freezing while working with HD video on the Samsung wave when the 8Gb memory card i use was half filled.

  7. Thanks for this valuable post.I have had this intuitive feeling all along about some of these memory cards but could not really place it.I have experienced my phones freezing.My thoughts then was that the demands the cards placed on the phones was too much hence the phone freezing but now I know much better all thanks to you.

  8. What a coincidence! Mr Yomi must be talkin to me… almost maxed out my 16g n8 internal memory so I told my cousin in d UK on Saturday to get me a 32gb card which his mom deliverd to me when she got to naija today. Just thot I check out mobility nigeria lo and behold I saw the frightening title PAY ATENTION TO DAT MICRO SD CARD … After reading I popped out the Kingston branded card and started scrutinzin it, couldnt find any classification then I started thinkin it was another fake like all the others(sandisk) I got from computa village in the past that made me loose important data several times… Was already angry and got a torch to check properly only for me to see a c4 then I smiled and thot I share my little testimony. Keep up the good work !! May you always be enligthened… Yeah, I got a problem with the n8 phone memory.. Wheneva I want to play Assasins creed hd game it closses all other runing apps to free enough memory to run the game,if the phone browser is running in the background the game wont load because its unable to close the browser unless I exit it myself… It keeps giving me a memory full message unless I exit ALL other runin apps, I have 170mb free phone memory, 3gb mass memory and an untouched 32gb micro sd card so why on earth can’t I multitask when I want to play the game which is a 231mb file? I don’t understand nokia, don’t know why I keep getin memory full message when nokia is supposed to be the king of multitasking… Any suggestion fellows?

  9. @TelNeting, This memory full message on Symbian. I do not much know abouut the Symbian^3 (on which your N8 runs). But I know for a fact that, on Symbian^1 on which my Nokia5800 runs, if you install too many applications on your phone (even on the Memory card!), you keep getting all sorts of memory errors. You may be unable to install some applications, or even install others .

    If you are like me and keeps installing and uninstalling numerous applications, your C: memory will gradually get cluttered, affecting the general stability of phone. Memory issues, speed and startup issue

    You should also check if you have lots of applications that automatically start-up when you switch your phone on. If they are too many, they may eat up your phone memory surreptitiously. Note that there are applications that run in the background (as processes) without them showing up in the task Manager. Sniff them out.

    You may – as a final solution – format your phone memory. do this by pressing *#7370#. Your phone memory (not memory card) will be wiped clean. For thoroughness and completeness, format your memory card as well. Of course, backup important data first.All should then be well.

    If [Assassin Creed] keeps ‘assassinating’ your memory, it may be a corrupted version (depending on on where/how you got it!). Did it come preinstalled on your N8?

    I will also suggest you get a capable memory manager like ‘Swiss Memory Manager Pro’ or RamBlow [both by by CellPhoneSoft]. They are capable.

    If all else fails, stop playing the Assassin. It is illegal! Or, throw away the Nokia N8, and buy a Nokia E7! :-d

  10. Lol, thanks for the funny but sensible suggestions… I think the problem is from the c:memory, I don’t store data on it but I have 170mb left out of 256mb.. Also realizd my messages are saved on the c:memory by default and I can’t change it to e: or f: unlike my e series.. does it mean I have to delete my messages all the time to save space on my c:memory ? Enh ? Nokiaa ? They should work on this… Where’s our forum member who is a nokia staff?

  11. @Eyebeekay
    Men! comedy would sell through you. I am still laughing.
    Telneting-dont let the Assasins assinate you or your N8-thats my dream phone

  12. I must confess i’ve never had a post so timely like this one.I’ve just finished discussing memory card’s issues with a friend without clue ,and VIOLA this is the solution. Gat Hi5 on this man!

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