在網路上購買的便宜裸裝 TF 卡，容量 32GB，一片只要 50元，大約是便宜的威剛同容量的 TF 卡的一半價格。
nexby，沒聽過的品牌，made in Taiwan，好像還不錯。
但是先前曾在淘寶買便宜的 TF卡，結果根本不能用。這次只敢買 3片，湊成免運。等確定可用再多買。
測試軟體，F3 (Fight Flash Fraud or Fight Fake Flash) ，可參考 f3read 及 f3write 指令說明。
安裝
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$ yay -Ss f3
$ yay -Ss f3
aur/f3 9.0-1 (+119 1.49)
Simple tool that tests flash cards capacity and performance to see if they live up to claimed specifications
$ yay -S f3
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測試
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# f3write /mnt/sd
F3 write 9.0
Copyright (C) 2010 Digirati Internet LTDA.
This is free software; see the source for copying conditions.
Free space: 28.49 GB
Creating file 1.h2w ... OK!
Creating file 2.h2w ... 5.93% -- 17.63 MB/s -- 42:07
.....
Creating file 28.h2w ... OK!
Creating file 29.h2w ... OK!
Free space: 16.00 MB
Average writing speed: 12.23 MB/s
# f3read /mnt/sd
F3 read 9.0
Copyright (C) 2010 Digirati Internet LTDA.
This is free software; see the source for copying conditions.
SECTORS ok/corrupted/changed/overwritten
Validating file 1.h2w ... 2097152/ 0/ 0/ 0
Validating file 2.h2w ... 2097152/ 0/ 0/ 0
Validating file 3.h2w ... 7.50% -- 18.15 MB/s -- 24:26
....Validating file 27.h2w ... 2097152/ 0/ 0/ 0
Validating file 28.h2w ... 2097152/ 0/ 0/ 0
Validating file 29.h2w ... 999072/ 0/ 0/ 0
Data OK: 28.48 GB (59719328 sectors)
Data LOST: 0.00 Byte (0 sectors)
Corrupted: 0.00 Byte (0 sectors)
Slightly changed: 0.00 Byte (0 sectors)
Overwritten: 0.00 Byte (0 sectors)
Average reading speed: 18.30 MB/s
測試結果比較 (2025年 5月)
1) 二手 innodisk 宜鼎工程用 8GB MLC長效記憶卡
=> Average writing speed: 6.87 MB/s，Average reading speed: 15.66 MB/s
2) ADATA 32GB，A1 / V10
Average writing speed: 10.96 MB/s，Average reading speed: 17.09 MB/s
3) 無名 nexby 32GB，U1
Average writing speed: 12.23 MB/s，Average reading speed: 18.30 MB/s
看來便宜的無名 SD 卡表現不錯，至於工程卡，終究是早期的產品，有點慢。
