The microSD card is the most underrated part of a retro handheld console, and yet the one that causes the most failures. By the end of this guide you will know how to decode the speed classes, understand what the A1 and A2 markings mean, choose a capacity that matches the systems you play, decide between FAT32 and exFAT, spot a counterfeit and check a card before trusting it with your saves.
What you need
- A reliable microSD card reader, preferably USB 3.
- A computer running Windows, macOS or Linux.
- A tool to test the real capacity and a tool to measure throughput.
- Your console's spec sheet, to know the maximum supported capacity.
Step 1: decode the markings printed on the card
A microSD card displays half a dozen symbols, and most of them have nothing to do with the use we care about here. Here is how to rank them.
Sequential speed classes
The number inside a U (U1, U3) and the V marking (V10, V30, V60) indicate the guaranteed minimum rate for continuous writing. These values were designed for video. For a retro console, they mainly matter at the moment you copy your files across. In game, their influence is marginal.
The A1 and A2 classes, the ones that really count
The A1 or A2 marking refers to random access performance, that is to say the ability to read a multitude of small scattered fragments. That is exactly what an emulator does when it loads textures, browses a disc image or displays a list of several thousand entries with their box art. A1 guarantees 1500 read operations per second, A2 guarantees 4000.
In practice, A1 is the right floor for a retro handheld console. A2 brings a gain on recent Android machines, but it depends on hardware support that is not universal. An A2 card in a machine that does not make use of it behaves like an A1.
What is useless
Marketing claims such as "4K optimised" say nothing about random access. A card sold for video can post an excellent V30 and crawl on small files.
Step 2: choose the right capacity
There is no point in reflexively going for the maximum. The useful capacity depends on the systems you play, because game sizes vary enormously between generations.
- 8-bit and 16-bit systems (monochrome handhelds, home consoles of the era): files weigh a few kilobytes to a few megabytes. A low-capacity card is more than enough for hundreds of titles.
- 32-bit systems and more recent handhelds: you move up to a few dozen or a few hundred megabytes per game. A mid-capacity card becomes comfortable.
- Optical-disc systems and 3D consoles: each game can weigh several gigabytes. This is where large capacities make full sense.
Two limits should guide your choice. First, the maximum capacity supported by your console, which varies from model to model: check the product page or ask our customer service. Then common sense: a very large card concentrates all your risk on a single medium. Two mid-size cards are often better than one huge one.
Step 3: FAT32 or exFAT, how to decide
The file system determines how data is organised on the card. Two formats dominate, and the choice is not trivial.
FAT32
Maximum compatibility. This is the format that retro console interfaces recognise most reliably, especially machines running embedded Linux. Its major limitation: no individual file can exceed 4 GB. For the vast majority of retro systems, you will never run into that limit. It becomes a nuisance as soon as you handle large disc images.
exFAT
No file size limit in practice, and more flexible handling of very large capacities. In exchange, exFAT is less universally supported by retro interfaces and is more sensitive to abrupt power-offs.
The simple rule: keep the original format of the card supplied with the console. If you are preparing a new card, favour FAT32 for older systems, and exFAT only if you need files larger than 4 GB and your machine handles it. Depending on the model, some consoles use several partitions: reformatting the system card then wipes the firmware. Never do it without a complete copy.
Step 4: spot a counterfeit and test the card
Fake microSD cards are a scourge of the grey market. The principle is always the same: a low-capacity chip is reprogrammed to announce a fanciful capacity. The card accepts files without complaint, then silently overwrites data once the real capacity is reached. You discover the problem when you find that half your games and saves are corrupted.
Warning signs at purchase
- A price far below the market for a large capacity.
- Sloppy packaging, blurry printing, a misaligned logo.
- A third-party seller with no track record on a marketplace.
- An advertised capacity that does not exist in the manufacturer's official range.
Test a new card, every time
- Insert the card into a reader connected to the computer.
- Run a real-capacity verification tool, which writes data across the whole volume then reads it back to compare.
- Let the test run to completion: on a large capacity, expect several hours.
- Check that the validated capacity matches the advertised capacity, allowing for the usual conversion margin.
- Then measure read and write throughput with a benchmarking tool.
This test only costs machine time. Do it before copying anything, since it erases the contents of the volume.
Common mistakes
- Choosing capacity over speed. A large card with no A1 marking will make your menus sluggish and your loading times long. For the same budget, a more modest capacity with A1 or A2 offers a far better experience.
- Reformatting the original card without a copy. On many models, that card holds the system. One quick format and the console no longer boots. Always make a complete copy of the contents onto your computer before doing anything.
- Using exFAT on a machine that cannot handle it. The console then simply ignores the card, or displays no games at all. Go back to FAT32 if in doubt.
- Removing the card without ejecting it properly. This is the number one cause of corruption. Always eject through the operating system, and shut the console down completely before pulling the card out.
- Trusting a card found in a drawer. An old card may have worn out its cells and keep accepting writes while losing data. Test it before trusting it with your saves.
Frequently asked questions
Is an A2 card really faster than an A1 in game?
It depends on the machine. A2 relies on a caching mechanism that not every controller makes use of. On a retro console running embedded Linux, the gain is often nil. On a recent Android machine loading heavy systems, it becomes noticeable. When in doubt, A1 remains the safe choice.
Do you need a brand-name card?
Yes, and above all one bought from an identified retailer. The major brands supply components that match their advertised specifications and a warranty you can actually use. The main risk does not come from the brand but from the distribution chain, where counterfeits with perfectly imitated logos circulate.
Can I use two cards in the same console?
Depending on the model, some machines have two slots, one reserved for the system and the other for games. It is a comfortable configuration: the system stays intact and you can swap the game card freely. Check your console's product page or contact our customer service to find out the exact configuration of your model.
How long does a microSD card last?
There is no universal answer. Flash memory wears out as you write to it, and a card can stop working with no warning sign. The only real protection is to copy your saves onto a computer regularly.
Going further
Once the card is chosen and tested, move on to filling it up with How to add games to a retro handheld console, then put your saves out of harm's way with Backups: never lose your progress again. If you are considering changing interface, read Alternative firmware: should you install one? first
Discover our selection of microSD cards, our Anbernic consoles and our handheld consoles.