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153 lines
6.1 KiB
Markdown
153 lines
6.1 KiB
Markdown
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title = "Testing a $4 Micro SD Card From AliExpress"
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date = 2024-04-07T15:06:25+10:00
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#[extra]
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#updated = 2024-02-21T10:05:19+10:00
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+++
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I needed three low capacity micro SD cards for an upcoming project. There's
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plenty of these available on AliExpress but its very difficult to know if you
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if the actual capacity will match the packaging. I did some research and came
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across [this interesting video][video] that tested 16 different cards. Their
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recommendation was the Lexar ones. So I found [some 32Gb ones for
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AU$4.13][mycards] and placed an order[^1].
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{{ figure(image="posts/2024/testing-aliexpress-sdcards/lexar-32gb-micro-sd-card.jpg", link="posts/2024/testing-aliexpress-sdcards/lexar-32gb-micro-sd-card.jpg", alt="Photo of the micro SD card in its packaging.", caption="The card being tested.", resize_width=880, width=440) }}
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As per the video's suggestion I tested one with an open-source tool called
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[F3 (Fight Flash Fraud)][f3] when they arrived. F3 verifies the capacity against
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what the drive advertises and verifies that that amount of data can be written
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and read back without error.
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<!-- more -->
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The card passed all tests. The packaging said up to 100MB/s read and is marked
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C10/U1/V10, which is minimum 10MB/s sequential write. The tests showed a
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write speed of 30.7MB/s and a read speed of 90.9MB/s, which feels within the
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values advertised.
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No idea what the endurance of the flash memory will end up being but I intend
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to use them in a low-write environment, where failure doesn't really matter. If
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the data the cards was storing was not easily replaced, such as photos, I
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would still purchase from a repeatable local seller. However, for holding an
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operating system image for a non-critical single board computer these seem
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fine.
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### Full Results
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```
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$ doas f3probe --destructive --time-ops /dev/sde
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F3 probe 8.0
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Copyright (C) 2010 Digirati Internet LTDA.
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This is free software; see the source for copying conditions.
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WARNING: Probing normally takes from a few seconds to 15 minutes, but
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it can take longer. Please be patient.
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Good news: The device `/dev/sde' is the real thing
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Device geometry:
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*Usable* size: 29.54 GB (61952000 blocks)
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Announced size: 29.54 GB (61952000 blocks)
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Module: 32.00 GB (2^35 Bytes)
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Approximate cache size: 0.00 Byte (0 blocks), need-reset=no
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Physical block size: 512.00 Byte (2^9 Bytes)
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Probe time: 1'02"
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Operation: total time / count = avg time
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Read: 347.8ms / 4815 = 72us
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Write: 1'02" / 4192321 = 14us
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Reset: 0us / 1 = 0us
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$ f3write /run/media/wmoore/8BF0-E09E/
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F3 write 8.0
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Copyright (C) 2010 Digirati Internet LTDA.
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This is free software; see the source for copying conditions.
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Free space: 29.53 GB
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Creating file 1.h2w ... OK!
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Creating file 2.h2w ... OK!
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Creating file 3.h2w ... OK!
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Creating file 4.h2w ... OK!
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Creating file 5.h2w ... OK!
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Creating file 6.h2w ... OK!
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Creating file 7.h2w ... OK!
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Creating file 8.h2w ... OK!
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Creating file 9.h2w ... OK!
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Creating file 10.h2w ... OK!
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Creating file 11.h2w ... OK!
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Creating file 12.h2w ... OK!
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Creating file 13.h2w ... OK!
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Creating file 14.h2w ... OK!
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Creating file 15.h2w ... OK!
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Creating file 16.h2w ... OK!
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Creating file 17.h2w ... OK!
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Creating file 18.h2w ... OK!
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Creating file 19.h2w ... OK!
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Creating file 20.h2w ... OK!
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Creating file 21.h2w ... OK!
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Creating file 22.h2w ... OK!
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Creating file 23.h2w ... OK!
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Creating file 24.h2w ... OK!
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Creating file 25.h2w ... OK!
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Creating file 26.h2w ... OK!
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Creating file 27.h2w ... OK!
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Creating file 28.h2w ... OK!
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Creating file 29.h2w ... OK!
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Creating file 30.h2w ... OK!
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Free space: 0.00 Byte
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Average writing speed: 30.71 MB/s
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$ f3read /run/media/wmoore/8BF0-E09E/
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F3 read 8.0
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Copyright (C) 2010 Digirati Internet LTDA.
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This is free software; see the source for copying conditions.
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SECTORS ok/corrupted/changed/overwritten
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Validating file 1.h2w ... 2097152/ 0/ 0/ 0
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Validating file 2.h2w ... 2097152/ 0/ 0/ 0
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Validating file 3.h2w ... 2097152/ 0/ 0/ 0
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Validating file 4.h2w ... 2097152/ 0/ 0/ 0
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Validating file 5.h2w ... 2097152/ 0/ 0/ 0
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Validating file 6.h2w ... 2097152/ 0/ 0/ 0
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Validating file 7.h2w ... 2097152/ 0/ 0/ 0
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Validating file 8.h2w ... 2097152/ 0/ 0/ 0
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Validating file 9.h2w ... 2097152/ 0/ 0/ 0
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Validating file 10.h2w ... 2097152/ 0/ 0/ 0
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Validating file 11.h2w ... 2097152/ 0/ 0/ 0
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Validating file 12.h2w ... 2097152/ 0/ 0/ 0
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Validating file 13.h2w ... 2097152/ 0/ 0/ 0
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Validating file 14.h2w ... 2097152/ 0/ 0/ 0
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Validating file 15.h2w ... 2097152/ 0/ 0/ 0
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Validating file 16.h2w ... 2097152/ 0/ 0/ 0
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Validating file 17.h2w ... 2097152/ 0/ 0/ 0
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Validating file 18.h2w ... 2097152/ 0/ 0/ 0
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Validating file 19.h2w ... 2097152/ 0/ 0/ 0
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Validating file 20.h2w ... 2097152/ 0/ 0/ 0
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Validating file 21.h2w ... 2097152/ 0/ 0/ 0
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Validating file 22.h2w ... 2097152/ 0/ 0/ 0
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Validating file 23.h2w ... 2097152/ 0/ 0/ 0
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Validating file 24.h2w ... 2097152/ 0/ 0/ 0
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Validating file 25.h2w ... 2097152/ 0/ 0/ 0
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Validating file 26.h2w ... 2097152/ 0/ 0/ 0
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Validating file 27.h2w ... 2097152/ 0/ 0/ 0
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Validating file 28.h2w ... 2097152/ 0/ 0/ 0
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Validating file 29.h2w ... 2097152/ 0/ 0/ 0
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Validating file 30.h2w ... 1102208/ 0/ 0/ 0
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Data OK: 29.53 GB (61919616 sectors)
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Data LOST: 0.00 Byte (0 sectors)
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Corrupted: 0.00 Byte (0 sectors)
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Slightly changed: 0.00 Byte (0 sectors)
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Overwritten: 0.00 Byte (0 sectors)
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Average reading speed: 90.93 MB/s
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```
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[^1]: While these were branded Lexar there's really no way to know when ordering if they are
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genuine or not. The main thing I care about is whether they hold as much data as they say.
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[f3]: https://github.com/AltraMayor/f3
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[video]: https://www.youtube.com/watch?v=efwDleEJY2w
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[mycards]: https://www.aliexpress.com/item/1005005956657740.html
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