MicroSD card torture test writes 133 petabytes of data across 351 cards over three years — cards tested to failure reveal SanDisk as the outlier with 6 failures of the 7 tested

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There are many different options available if you want to buy a microSD card, but which one of these lasts the longest? Tech enthusiast Matt Cole wanted to find out, so he set up a torture rig in 2023 to put various cards through their paces and recently released an update on the status of his project on the r/DataHoarder subreddit. Cole said that he has a total of 351 microSD cards in his collection coming from 52 different brands and 111 unique models. Of these, 177 have already been tested until they completely stopped working, have become read-only, or more than half of the sectors on the card have experienced verification failure. Another 107 units are currently being put through their paces, while a further 67 are waiting for a microSD card slot to open up.

Cole has so far tested 200 cards last year, meaning 84 microSD's have failed in the intervening months. While this might sound disastrous for any manufacturer, we should note that the testing conditions are quite extreme, and it’s rare that a user would find themselves in these circumstances. If you want to check out the raw data, Cole’s database is publicly viewable on his website, but he’s also shared some of his observations after three years of testing. First, he divided his microSD cards into three categories: consumer-grade, high-endurance, and industrial-grade. Consumer-grade microSD cards are the typical cards you can get off Amazon, while high-endurance models are often labeled as such (or some other similar wording). Lastly, industrial-grade microSD cards are those that are specifically designed for heavy-duty use and would often come with a data sheet and an endurance claim.

According to the test results, the average consumer-grade microSD withstood 10,000 program/verify/erase cycles, with PNY, Kingston, Delkin Devices, Lexar, and Samsung rounding out Cole’s top five brands.

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Brand

Failed

Total Tested

Average Lifespan (Days)

Average Cycles

Total Written Data (PB)

PNY

1

10

643

15,700

11.5

Kingston

3

12

694

23,500

11.6

Delkin Devices

0

3

662

13,500

5.1

Lexar

3

8

684

15,800

5.8

Samsung

3

10

553

11,100

7.2

Interestingly, Amazon Basics received an honorable mention, with none of the microSD cards being tested failing yet. They’ve been running for 788 days now, with 16,600 cycles and a total of 4.2PB of data written on them. The only reason they didn’t make the main list is that they’re technically generic or off-brand microSD cards and Amazon could replace the NAND chips used in these cards anytime, thereby making the survey results moot. There’s a separate shorter list for high-endurance and industrial-grade cards, given that the sample size is just smaller and the latter is significantly more expensive than all the other microSD cards available here.

Swipe to scroll horizontally

Brand

Failed

Total Tested

Average Lifespan (Days)

Average Cycles

Total Written Data (PB)

TEAMGROUP (High-Endurance)

0

2

404

17,300

2.2

Transcend (High-Endurance)

0

3

760

17,000

3.2

SanDisk (High-Endurance)

6

7

452

16,200

4.7

Samsung (High-Endurance)

1

3

822

18,800

1.8

Kingston (Industrial-Grade)

2

3

77+

141,600

3.4

He also listed some of the worst performers per category from popular brands, like ADATA, Gigastone, Micro Center, Silicon Power, and, surprisingly, SanDisk, although Cole avoided no-name brands, since most users don’t expect much from them.

Doing all these tests simultaneously and continuously is no joke, and we see this in Cole’s setup. He runs a single Beelink Mini-S with an Intel N95 CPU, 8GB of RAM, and a 500GB SSD, five TRIGKEY Green G4 mini-PCs and one TRIGKEY K-N100 with an Intel N100 CPU, 16GB of RAM, and a 500GB SSD, and an AOOSTAR mini-PC with an Intel N150 CPU paired to 12GB of RAM and a 500GB SSD. Aside from these mini-PCs, he also has an MSI GE62VR-7RF Apache Pro laptop with an Intel Core i7-7700HQ, 32GB of RAM, and a 1TB SSD, a Lenovo IdeaPad Y850 laptop with an Intel Core i7-3630QM, 8GB of RAM, and a 1TB SSD, and an ASUS ROG Strix Hero II GL504GM laptop with an Intel i7-8750H, 32GB of RAM, and a 500GB SSD.

Running this experiment can get expensive as Cole needs to purchase all the microSD cards himself (unless someone donates them), especially at a time when memory card prices are skyrocketing. Aside from that, he also needs to purchase and maintain all that testing hardware. Although these are either relatively affordable mini-PCs or used gaming laptops, the cost of acquiring and running all these units will eventually stack up.

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Jowi Morales
Contributing Writer

Jowi Morales is a tech enthusiast with years of experience working in the industry. He’s been writing with several tech publications since 2021, where he’s been interested in tech hardware and consumer electronics.

  • chaz_music
    It is great to see an article like this on TH. This kind of stress testing is done all the time in engineering design and product quality assessment, and it is a great tool for finding where your margins are for a given stress type. If you test to failure, it is call HALT testing, and if you use it to act as hurdle, such as for manufacturing, it is called HASS test. In manufacturing these tests might be burn-in testing or hipot testing (insulation system verification).

    Knowing that Flash memory lifespan is also temperature dependent, the testing done in the article would have been even more interesting if the internal controller temp could be recorded while it was running, or conversely, if the ambient temperature had been set differently with two samples of each memory card (but - twice the cost of the study). If you move two stressors around at the same time, it is called a MEOST test.

    It is unfortunately that the GPU industry did not do this for the power connectors and used temperature and humidity as the stressors. They would have found that there exists a problem before even launching the product. But note - delaying a product launch is often a career damaging move at many companies. I myself have had my job threatened for stopping a product launch to fix an issue.

    All of these concepts can be found on Wikipedia where some people have done a great job explaining the ideas. If I remember correctly, these test methods were originally proposed in US academics around the mid 1950's, but not really used in industry until the Japanese automakers started utilizing them. I have used them successfully myself many times to find difficult failure modes in designs, and chasing root failure modes in warranty cases.
    Reply
  • Faiakes
    Sandisk among the failures? Seriously?
    This really worrying.
    They are the most or second most common brand.
    Reply
  • USAFRet
    Faiakes said:
    Sandisk among the failures? Seriously?
    This really worrying.
    They are the most or second most common brand.
    How is that worrying for SanDisk?
    ALL brands had fails.

    Given the amount of data was seen before the fails, this is like when buying a new car.

    Comparing Ford, Chevy, Toyota, Nissan.
    Looking at the published top speeds:

    Ford - 152mph
    Chevy - 155mph
    Toyota - 151mph
    Nissan - 154mph

    And then concluding TOYOTA SUX!!!!
    Reply
  • Nate1994a
    Faiakes said:
    Sandisk among the failures? Seriously?
    This really worrying.
    They are the most or second most common brand.
    Another thing is it seems like he's using different computers and therefore different readers and hardware configurations for it, so that's at least one or two possible variables not being accounted for from what I've read in the article.
    Unfortunately there no way of knowing if the SD readers themselves are part of the failure rates because we don't know what's being used.
    Reply
  • Sluggotg
    USAFRet said:
    How is that worrying for SanDisk?
    ALL brands had fails.

    Given the amount of data was seen before the fails, this is like when buying a new car.

    Comparing Ford, Chevy, Toyota, Nissan.
    Looking at the published top speeds:

    Ford - 152mph
    Chevy - 155mph
    Toyota - 151mph
    Nissan - 154mph

    And then concluding TOYOTA SUX!!!!
    If you look at the chart, SanDisk had 6 out of 7 fail. When you add up the other 4 companies, they had 3 out of 11 fail. That is a very high failure rate compared to the others. I think most people would be concerned by the high failure rate.
    Reply
  • USAFRet
    Sluggotg said:
    If you look at the chart, SanDisk had 6 out of 7 fail. When you add up the other 4 companies, they had 3 out of 11 fail. That is a very high failure rate compared to the others. I think most people would be concerned by the high failure rate.
    And again, what was written is FAR more than what one would actually do.
    "They lasted an average of 452 days and about 16,200 program/verify/erase cycles before failing (with the MAX ENDURANCE 32GB's lasting about twice as long as the High Endurance 64GB's). I've written about 4.7PB to these cards in total."

    When pushed waaaaaay out on the edge (4.7PB), yes, the SanDisks failed more than the others.
    But that has exactly zero to do with real world longevity.

    4.7PB across 7 drives = 670TB each (if distributed evenly)
    Now really...how much are YOU actually going to write across similar drives.
    Reply
  • markhahn
    The endurance reported here implies that the cards are using MLC (around 10k cycles spec). Is this even possible? It seems like fabs have been converted to TLC for years, and even QLC has been pushed across the market...
    Reply
  • markhahn
    Nate1994a said:
    Another thing is it seems like he's using different computers and therefore different readers and hardware configurations for it, so that's at least one or two possible variables not being accounted for from what I've read in the article.
    Unfortunately there no way of knowing if the SD readers themselves are part of the failure rates because we don't know what's being used.
    Isn't this pretty trivial? The computer shouldn't matter unless it's badly broken (reporting writes that it doesn't perform). It's not as if different computers can just decide to write to storage differently, since the media must always be in canonical format/ordering/etc.

    If the SD adapters are failing, it should be simple to verify.

    The one row of the data I looked at averaged 68 MB/s, which is reasonable, but probably implies that the load generator is not writing, then verifying each write. It's entirely reasonable that a motley collection of low-end computers could sustain this rate (though of course we have to toast the experimenter's fortitude as much as the SD cards' endurance!)
    Reply
  • Razzi16
    His comments about SanDisk make no sense at all.
    In the title he says "SanDisk as the outlier with 6 failures of the 7 tested", but in the actual table of testing results it says 3 failed out of 10 tested for SanDisk.
    So, which is it?
    Reply
  • SirStephenH
    Razzi16 said:
    His comments about SanDisk make no sense at all.
    In the title he says "SanDisk as the outlier with 6 failures of the 7 tested", but in the actual table of testing results it says 3 failed out of 10 tested for SanDisk.
    So, which is it?
    I thought I read 3 out of 10 too, but I went back to double check and the only thing that matched that was Samsung on the consumer list. SanDisk is on the high endurance list with 6 out of 7 failures. 🤷‍♂️
    Reply