Do Camera Memory Cards Wear Out?

The short answer: yes, they do. But maybe not in the way you might think.

Camera memory cards are surprisingly tough little things. In many cases, much more resilient than the camera itself.

They can tolerate a lot more than most cameras can. They can breeze through airport security X-rays without a hitch, don’t mind being dropped, are immune to magnets, often emerge unscathed from an accidental run through a washing machine, and, if you’re really lucky, can even last for a good stint submerged in sea water.

Manufacturers even go so far as to officially claim on the packaging and marketing materials that their SD and microSD cards are:

• waterproof
• temperature proof
• x-ray proof
• magnet proof
• drop proof
• wearout proof

That’s a lot of proofs!

But all flash memory cards can wear out. Not easily, and not quickly, but eventually.

Physical wear & tear isn’t the problem

The problem isn’t physical wear and tear. That’s rarely going to be an issue in practice, although it is possible for the contacts to become dirty or develop a thin layer of grime on them that can interfere with data transfer.

I’m focusing here on SD cards and microSD cards, but other memory card types with different form factors typically also have ruggedized builds.
All use NAND Flash memory, which is susceptible to the same kinds of write cycle limitations.

Here’s an example of the kind of internal testing that manufacturers put their cards through in order to be able to make their claims. In this case, it’s Samsung’s testing of microSD cards:¹

• Water: 72 hours in one-meter depth of seawater
• Wearout: a durability test of 10,000 swipes
• Drop: up to 5 meters (16.4 feet)
• Magnet: up to 15,000 gauss (equivalent of a high-field MRI scanner)
• X-ray: up to 100mgy (equivalent of airport X-ray machines),
• Temperature: -13°F to 185°F (-25°C to 85°C) operating, -40°F to 185°F (-40°C to 85°C) non-operating.

The problem is erase cycles

But if physical wear and tear isn’t really a concern, a more serious risk in the long term is wear and tear on the NAND flash.

It’s not a short-term risk; these cards are designed to handle tens of thousands or hundreds of thousands of hours of video data being written to them (also expressed as Total Bytes Written, or TBW).

But it is something to be aware of nonetheless, for two reasons:

1. To anticipate that old, heavily used memory cards will eventually need replacing.
2. To minimize unnecessary wear and tear from excessive full-format operations.

Write cycles end of life

NAND Flash memory, which is used in memory cards, thumb drives, and SSDs, has a finite lifespan in terms of how many times data can be written to it.

To be clear, it’s a lot of data that most photographers will only reach over the course of years. But there is nevertheless a finite endpoint. And now that we’re decades into the age of digital photography, it’s entirely possible for us to have memory cards from years ago.

If a card does hit its absolute limit, it enters an End of Life (EoL) state. The card’s controller will permanently lock the drive to prevent data corruption. If you are lucky, it locks into a “read-only” state, allowing you to recover your files. If you aren’t, the card simply dies.

There are, however, several precautions that are built into the actual memory card itself to help maximize the lifespan of the card. They have built-in algorithms that control what’s known as wear leveling, essentially spreading the load evenly across the sectors of the card to reduce the risk of a single area bearing the brunt of the workload.²

NAND Flash has limited program-erase cycles available. Reaching that limit means the device is in EoL state, meaning that it is no longer reliable. Endurance varies depending on the NAND cells’ configuration.³

Full format vs quick format

I have a more detailed description of the difference between quick format and full format options that your camera might offer, but the short version is that, for day-to-day use, a quick format is sufficient for most uses.

In a quick format, the camera (or host device) will delete the references to the data, but it won’t actually overwrite the underlying data itself. It simply wipes the File Allocation Table (FAT), meaning this process is nearly instantaneous and causes virtually zero wear on the card’s memory cells.

Some cameras also offer the option of doing a full format (also known as a low-level format). That’s a much more thorough process that actually overwrites the underlying data by writing zeros to every single block on the card. It takes longer. It’s more secure. It can help with maintaining the health and efficiency of the memory card if the card has been glitching. But because it forces a heavy write operation across the entire drive, used excessively, it can also reduce the lifespan of the memory card.

Anticipating potential problems

Unfortunately, though, as low as the risk of wearing out a card is, if the card is going to go, it will probably go suddenly without warning.

So it’s a good idea to build sensible precautions into your workflow to minimize the risks of losing large numbers of images if something goes wrong.

That means having backup cards on hand, downloading your images regularly, and formatting the cards in the camera after downloading the images.

There’s no hard-and-fast rule on how often you should replace your memory cards; it’s something to start thinking about when you’re getting up into the millions of images on a card (or hundreds of thousands if your card is an older model). Of course, if you’ve shot that many images, chances are you also have to start worrying about the failure of the camera itself. But that’s another story . . .

Tips for using and caring for your memory cards

• Like just about any product, especially an electronic one, it is possible for a brand-new memory card to be faulty. So always check that it’s working normally before you head off on that once-in-a-lifetime trip.
• Always format the card in the camera rather than on your computer. While the latter might well work, camera and card manufacturers usually recommend doing it in the camera to avoid data errors. It’s the safer option.
• Always download the images to your computer as soon as practicable and edit and archive from there. Trying to edit images directly on the memory card can lead to problems, and flash memory cards are not designed for long-term archival storage. The editing process introduces just the type of unnecessary write cycles described above. Treat them as a temporary step between your camera and your fully backed-up image archive.
• Always have a spare. Or two.
• Replace the cards on a schedule that makes sense for the type of shooting you’re doing. If you only take occasional snapshots, every couple of years might be fine. If you’re a working pro wedding photographer or sports photographer taking hundreds or thousands of shots day in day out, much more often is a better idea.

Notes & References:

1. “Samsung Unveils New PRO Endurance Memory Card Optimized for Surveillance and Dashboard Cameras,” Samsung Newsroom, 3 May 2022; “Samsung micro SD UHS-I Card: EVO Plus Lineup: 2023 Data Sheet (Revision 1.0)” Samsung, undated. [↩︎]
2. In addition to wear leveling, these built-in processes also include block management, garbage collection, and error control. Wear leveling works better the more space it has to work with, meaning that high-capacity storage can have higher endurance. [↩︎]
3. Kingston Technology, “eMMC Life-Cycle Estimating, Validating & Monitoring,” January 2023. [↩︎]