
It is a truism that no matter how much data storage capacity one has, in any context, one always fills it and wishes for more. There is a continual leapfrogging as between new applications and the new larger amounts of data they need; and the more or less balancing effects via increasing capacity and reducing cost of our hard drives, memory sticks, and other forms of storage.
Moore’s Law has reaffirmed itself yet again, with the latest doubling in micro SD card capacities. Previously the maximum capacity for these tiny things (less than half the size of a postage stamp and only slightly thicker) was 128 GB, even though full size SD cards are usually available in greater capacities. Now we have both an unusually sized 200 GB item that defies the traditional ‘powers of two doubling’ and a new ‘traditional’ sized 256 GB card too.
The best part of this news is that prices continue to ease. A year or so back, a 128GB card cost about $110, and the ‘sweet spot’ in terms of GB per dollar spent was either 32GB or 64GB, with a typical cost of about 50c/GB at those capacities. Now, on Amazon, the 128 GB card is about $30, and if you are brave enough to choose a ‘no-name’ brand, you can find them for even less. You’re paying the same price as a 64GB card barely a year back, and getting not just twice the memory, but the much greater convenience of having more data on one card and not having to swap cards all the time. Which leads to :
How Much Micro SD Capacity Do You Need?
The answer to this of course depends on the context you are using the card, and also circles back to our opening comment – you need more than you think!
If you are using the card in a personal music player and your total music collection only totals 20GB and you have no plans to ever increase it, then a case could be made to say that merely a 32GB card would be sufficient. (But if you then convert your music from MP3 to FLAC and need four times as much capacity, you’ve just illustrated the truth of the adage, yet again!)
On the other hand, if you are using a memory card in an HD or 4K camcorder, you’ll proably want the greatest capacity possible. Let’s consider some of the uses you may have for a Micro SD card.
The Main Travel Uses for Micro SD Cards
We suggest there are several completely different types of use that Micro SD cards have for us ‘on the road’. Maybe you can use one card interchangeably in these different roles, but more likely, you will have different cards in different devices, all at the same time.
1. Data Capture
The first use is as a data capture store – in your camcorder, camera, or phone/tablet to store primarily video and also regular photos. Regular photos probably use about 2.5 – 5 MB per photo, so you get in the order of 200 – 400 per GB, which means for most purposes, a lower capacity card would hold sufficient photos for most normal duration travels. We also like not having ‘all our eggs in one basket’ and we deliberately keep our camera card capacity moderately low, so that if we lose the camera or the card, we don’t lose our entire life’s store of pictures. Yes, we also back them up, too.
But as soon as you start to consider adding video clips, your need for storage capacity massively increases. It varies a bit depending on the resolution and compression factors, but moderately good HD video these days requires about 2 – 3 MB per second – as much as 10GB/hr. While the three hour capacity suggested by a 32 GB card might seem ample, it probably isn’t! That’s not to say that you need 256 GB, but certainly you should have at least a 64 GB card in anything that might be capturing HD video.
2. Movies and Music Storage
The second use when traveling is to ‘bring entertainment with you’. MP3 type music players have been common for 15 years now, most notably the iPod line of music players, although, going against the trend of ever higher capacity units, their biggest 160GB unit (with a small hard drive inside) has ceased production (in favor of the more modern style iPod with touch screen).
The MP3 music compression standard was designed at a time when disk space was more precious than music quality, and when concerns about music piracy also encouraged the studios to deliberately ‘cripple’ the quality on MP3 recordings. If you wanted good quality music, you had to buy the CD. These days, the state of the art has moved forward, and it is no longer necessary or best to store your music in MP3 format. Much better now to use the FLAC format, which uses 3 – 6 times more storage per minute of music than does MP3 (depending on the MP3 settings you were formerly using). FLAC music is exactly the same as CD quality, and typically just over half the size of a CD music file – an hour of FLAC music will require about 335MB. So a typical CD with 45 – 55 minutes of music on it is probably about 300 MB – three CDs per GB of storage.
However, getting an hour of music for 335MB of storage is a ‘bargain’ compared to the space you need to store video. If you want to copy movies and tv shows from DVDs (and Blu-rays, or downloaded from services such as Amazon Video) and take those with you as well, your storage requirements increase substantially. It depends on the compression and quality, but as a rule of thumb, you can figure on each hour of video in reasonably good quality requiring about 2.6 GB – a typical movie, just under two hours in length, will require almost 5 GB.
So how many movies do you want to have stored on your device? Amazon Prime Video lets you have up to 25 of their Prime movies (or tv episodes) downloaded at any one time for free.
Maybe you also have some eBooks on your device too; happily, those are usually very modest in storage; text only eBooks require a trivial amount of space (under 1 MB), but if the book is illustrated, then they start to require some number of MB, but still a relatively trivial amount of space compared to movies and music.
So, a book or two, a few movies and some CDs, and you’re quickly exceeding 64 GB, and possibly starting to explore the limits of 128 GB.
Now, here’s a key consideration. Sure, you could split all your data over multiple 32 GB cards, or even over twice as many 16 GB cards. But it is so much more convenient just to have everyone on one single card, meaning that you can browse through your entire library of content without having to shuffle Mini SD cards (they are so small that they are almost ‘too small’ from a convenient/easy to handle point of view and plugging them in and out of devices is sometimes a fiddly and difficult process). You also don’t have to worry about losing one or more of them – if you only have one, and it is inside your device, it becomes much harder to lose it.
Another consideration is that sometimes your device comes in different configurations, offering varying amounts of internal storage as well as an external Micro SD slot. Almost always, it is much less expensive to buy the device with less built in storage and to supplement that with more external storage.
3. Data Backup and Recovery
We suggest that increasingly there’s a third valid purpose for SD and Micro SD cards. The chances are you use some sort of backup system at home or work (and if you don’t, you should – these days it is so easy and affordable). But what happens when you’re traveling?
If your regular backup tool of choice is one of the cloud/internet based services, that is absolutely not a good choice for when you’re on the road. Way too many Wi-Fi connections are open and insecure, and you’re potentially transmitting all your most secure and sensitive data over a public Wi-Fi channel. In addition, many times internet access is slow, and sometimes it is even charged by the GB, making this type of internet access terribly inconvenient and unwieldly and also adding appreciable extra costs to your Wi-Fi access charges.
If you use either some type of corporate backup system or, more simply, an external harddrive alongside your computer, those are not necessarily conveniently portable and easy to take with you.
Think also that your laptop is at greatest risk when you travel. It might get dropped or in some other way physically damaged. It might get stolen. I have had my laptop’s OS get garbled due to an internet connection failing half-way through an update. Whichever way these things might happen, you might find yourself needing the ability to recover your data, or alternatively, if your laptop fails or disappears, you don’t want to also have lost a week or two of work that was accumulating on it.
A regular SD card, or a Micro SD card (and probably in a regular SD card adapter) is the best way to take data with you when traveling. It is physically robust – you can drop it, get it wet, and generally moderately abuse it without consequence. It is tiny and weighs next to nothing. It doesn’t require extra ‘stuff’ like a connecting cable or a power supply. Just plug it in and off you go.
Other Uses Too
There is a very new type of application where high capacity Micro SD cards are useful – for storing video being recorded on a drone!
Definitely something new and not a universal need we all have.
Choosing a Micro SD Card
So, after considering the preceding uses, maybe you actually need multiple cards for your multiple devices! There are a number of things to consider when selecting the cards you want – of course, price is obviously a factor, but there are many other issues as well.
Different Types of Cards and Capacities
There are three different types of Micro (and regular) SD cards. Originally, there were plain SD cards. These had a maximum capacity of 2GB per card (and used the FAT 12 or FAT 16 file system). Then came SDHC, which could store up to 32 GB of data, using FAT32. Most recently, we have the SDXC type cards, which can grow to an impressive 2TB in size (even though cards with that much storage haven’t yet been released, but their specification has that much addressable memory capacity). All three types of card are physically identical, but have prominent branding on them to show which type of card they are (see, for example, here for examples of the three different logos).
The significance of this relates more to the device you are plugging the card into than the card itself. If your device can only manage SDHC cards, then it will not be able to make use of a SDXC card’s additional memory above 32 GB.
On the other hand, the good news is that although many devices that do support SDXC cards will say in their specification ‘Supports up to 128 GB cards’, they actualy will support higher capacity cards too. The reason they say ‘up to 128 GB’ is not because they don’t/won’t/can’t support the new 200 GB and 256 GB cards; it is simply because, at the time the device was built and the specifications for it were written, such cards didn’t exist.
As far as we have been able to tell, all devices which say ‘supports cards up to 128 GB in capacity’ will actually support the higher capacity cards too. The only exception would be an artificial marketing limit – a company which deliberately limits the amount of external storage it can address, so as to encourage you to buy a more expensive ‘better’ version of the product. We know of some companies that claim an artificially lower limit for marketing reasons but which in really support higher capacity cards, we don’t know of any that truly don’t.
Different Speeds
There are three different ways of measuring card speeds these days. The three different ways can be more or less equated to each other, and the key thing to appreciate is that in all cases, the bigger the number, the faster.
The newest speed ratings are the UHS Speed Class ratings. UHS 1 is plenty fast enough for anything except highest quality 4K video filming, which would require UHS3 (and this assumes the device they are connected to is capable of sending/receiving the data at that speed, too).
The previous and still used speed rating was the Speed Class rating, with numbers from 2 up to 10. 2 is good enough for taking pictures one at a time and playing music, 4 is sufficient for most regular video, and 10 is appreciably better. The number represents MB/sec.
The original rating is to compare them to an old fashioned original CD drive, and or to show the speed as a raw MB/sec rating. But these numbers can be misleading – they are often ‘maximum’ speeds rather than sustained speeds, and might be five or more times higher than the real world speeds the cards are capable of. A 16x rating means ’16 times faster than an original CD drive’ and is about 2.3 MB/sec which is about the same as a Class 2 rating. Whereas there are standardized measures for Speed Class and UHS Speed Class, there aren’t for this other measure and so proceed with caution if your card does not also have a Speed Class or UHS rating on it.
Different Brands
This is an interesting issue. We don’t have substantial direct knowledge, but there is a lot of commentary that suggests it is risky to buy off-brand memory cards, and it has also been suggested there is a lot of counterfeiting of name-brand memory cards.
What are the risks and downsides? Memory chips are not a simple ‘yes it works/no it doesn’t’ type product. Instead, they have varying degrees of quality and performance. Some memory chips, made at the same time as others, are more likely to have errors reading and writing, and some can not manage as fast a speed for reading and writing.
So name-brand suppliers of memory tend to take the best chips from each manufacturing batch and accurately/honestly rate them. They either use the remaining chips by rating them at slower speeds, or possibly sell the inferior chips to some other company, and that other company might not rate them honestly.
One other astonishing pitfall can be that apparently some companies design their memory cards to pretend to have a higher capacity than they truly do. You might think you are getting a 128 GB card, and when your computer reads it, you are told it has 128 GB. But then you notice it fills up very quickly, and shows as full even though you know you’ve not put 128 GB of data on it.
We have never had a memory card that we didn’t need to be able to rely on, and which we weren’t trusting to store important data, so we’ve never risked buying a no-name-brand unit, even though the prices are temptingly lower than the name brand units such as SanDisk, Samsung, Sony, Kingston, probably PNY, and other ‘big names’ that you recognize – these would all be reasonably safe choices.

Other Considerations
Some cards have extended warranties – up to as much as 10 years on some Samsung cards, for example. While we don’t see much practical value in a warranty on a device that costs only a few dollars and is more hassle to return than just to buy a new one, there is an implication that if a company is willing to warrant their cards for an extended period, that suggests confidence in the longevity of their product.
Some Micro SD cards come with a regular SD card adapter, so they can be used with regular SD card slots. That is helpful, and even though I have lots of those adapters, I usually preferentially buy those cards if the price is the same, on the basis of ‘you can never have too many’. A few cards – not so many these days – have adapters for both mini and regular SD cards. The mini SD card is halfway in size between regular and micro cards, and was a technology that never really was widely used – it was superseded by the micro size almost as soon as the mini size came out. The danger of this type of dual purpose adapter is that there is a slight extra risk of bad data transferring if you have the Micro SD card then connecting through a mini card adapter and then in turn connecting through a full card adapter and finally then connecting to the device. The fewer the number of connections, the better.
One other thought. As touched upon above, Micro-SD cards are tiny. 25 of them together are barely an inch thick, and 50 of them together weigh only an ounce. Each one measures about 0.4″ x 0.6″. The technology that can now cram 256 GB of data into something that size is beyond stunning. On the other hand, consider that you can be paying up to $200 for one of these – that is $10,000 for an ounce of Micro SD cards – seven times the current price of gold!
But the downside of small and lightweight is they are easy to lose. I use a credit card sized ‘carrier’ that holds ten Micro SD cards and a regular SD card adapter, too. This is much harder to lose, and a great way of carrying and protecting the cards. Best of all, it costs a mere $6.94 on Amazon. There are lots of other carrier type products too, but this one is simple and ‘bullet proof’ and hard to improve upon. Sure, the orange is a rather garish color, but it makes it harder to forget about and ‘not see’.
Pricing
We recommend you generally should get 64 GB cards, 128 GB cards, or the new 200 GB card. On Amazon and with name brand cards, 64 GB cards cost about $18 – $22, 128 GB cards are about $30 – $40, and the 200 GB card is $80. A smaller 32 GB card is about $10, and the new 256 GB card is currently $200.
So the 128 GB card has the lowest cost per GB, but there is very little cost premium for the 200 GB card, making it a great choice if you think you’ll get extra value out of its much greater size. The 256 GB cards don’t make much financial sense currently, unless you absolutely need the extra 56 GB they offer.
Using Instead of Regular SD Cards, Too?
Regular SD cards are essentially identical ‘under the hood’ to Micro SD cards, That is why you can fit a Micro SD card into an adapter blank to allow it to plug in and out of regular SD card slots in devices.
They were formerly less expensive than Micro SD cards, but these days, there’s precious little difference between them in 128 GB or lower capacity formats. The only place where they become a better value is if you want to go to a 256 GB SD Card, which can be had for as little as $80 on Amazon, or if you wanted to explore an larger capacity 512 GB card ($190 on Amazon) that isn’t yet available as a Micro SD card. Traditionally, the regular SD cards tend to go up to a larger capacity than the Micro SD cards – the extra level of miniaturization to go down from SD to Micro SD seems to take another year or so. We understand that 1 TB (ie 1024 GB) SD cards are already on the horizon.
Some people choose to simply get Micro SD cards and use them for everything, everywhere, with an adapter if needed, and without if not. We have no opinion on that and can see reasons for or against, particularly at present because there’s no real financial issue either which way.
Summary
If you have devices that use Micro SD cards, you should be aware that the cards continue to drop in price and increase in storage capacity. With ever higher quality video and better music storage formats, we can benefit from more and more storage capacity available.
If you’ve not already upgraded to 128 GB cards, perhaps now is a good time to do so, and if you have larger requirements, the new 200 GB card, at only $80, is definitely the best choice.
Hold off on the very much more expensive but only slightly larger 256 GB cards until they drop in price to a more reasonable level.
Another consideration is whether your device can handle the high capacity cards.
Very true.
I cover that in the section, above, on Different Types of Cards and Capacities.
Why are you paying money for air travel? I never do. I use miles and Avios from big credit card signups.
Same for never paying for hotels but, instead, using points and free nights from credit cards.
By the way, my responsible use of credit cards has pushed my credit scores into the 800s.
I guess you either don’t travel much, or else spend huge amounts of money on a credit card.
I’m not saying I travel a lot, but so far this year I’ve converted about 250,000 miles (from spending about $250,000 at a rate of one mile credit per dollar spent) into two roundtrip tickets, and my most recent trip was going to require another 100,000 miles (just for coach class roundtrip to Europe) and I only had 85,000.
Jerry, I also rarely pay for air travel – but when you travel a lot, you do not always have enough miles – especially if you like business class for longer flights. And if you use the Avios, you still have to pay quite a bit for the “taxes and fuel surcharges” even if on the 2 for 1 voucher. Or do you have a way around it for B.A.??
As to hotels, you really need a lot of points to avoid paying cash if you travel very much. And if you get out of the main towns, often no Hiltons, Marriotts, Starwoods, etc. and then not many low priced like Fairfield, Hamptions, etc. Try the French/Spanish Pyrenees area. You really miss something if you don’t stay in the small towns and savor the local lifestyle. We do hit the tourist sites, but also get off the beaten track about 1/2 the time.
Identifying the speed of a microSD card is just as complicated as deciphering formats and compatibility. There are four ways to show how fast a card is, and it’s not uncommon for manufacturers to use all of them.
David,
Thank you for the excellent write-up on these cards/chips. I’ve seen these things everywhere and all over the map price-wise. I have a port on my laptop that is almost 3 years old and on my new printer at home but have never considered buying those things, I tend to opt for the flash drives for my backups which have likewise jumped in GB capacity and dropped in price to almost nothing.
You seemed to have done a great job covering this, answering all questions I have at the moment.I may mix up my choices on my backup devices. I never dropped movies to these things but maybe in the future….
thanks again