Benchmark flash memory on Linux

After gathering all flash based memory devices (USB flash memory sticks and SHDC cards) I could get my hands on I wanted to see how they compare to each other.

Quick google search revealed that dd tool could be used for benchmarking so that is what I used. Have you done benchmarks some other way? Please share your method.

Be really, really careful if you choose do to write test, because that will ERASE your existing data so test write speed only on EMPTY flash memory devices. Also triple check which device is your flash memory device. Simple typo could render your data partition unusable!

I didn't want to write on the first 1GB of flash memory because that part is probably most often used, I know there are some wear-leveling chips that should take care of that but you can use skip parameter if you wish to be safe. To prevent measuring your cache performance but actual device performance use iflag and oflag options.

read speed benchmark:

sudo dd if=/dev/sdX1 of=/dev/zero bs=1M count=400 iflag=direct

write speed benchmark:

sudo dd if=/dev/zero of=/dev/sdX1 bs=1M count=400 skip=1000 oflag=direct


USB memory stickRead speedWrite speed
8GB MX-ES SLC USB 3.0149 MB/s61.9 MB/s
64GB Corsair Voyager Vega USB 3.0102 MB/s35 MB/s
16GB PQI Mini U603V USB 3.0103 MB/s12.5 MB/s
8GB Kingston DT 2.019.0 MB/s16.0 MB/s
8GB Kingston DT SE920.1 MB/s14.9 MB/s
2GB Transceng VF V9019.2 MB/s11.6 MB/s
4GB Red USB19.8 MB/s9.0 MB/s
64GB Kingston DT SE919.5 MB/s8.3 MB/s
4GB Kingston DT 10815.2 MB/s7.2 MB/s
8GB Silicon Power SP 81024.8 MB/s5 MB/s
SDHC CardRead speedWrite speed
SanDisk Ultra 32GB mini class U370 MB/s48 MB/s
Swissbit 2GB mini class unknown22 MB/s18 MB/s
Samsung 32GB class 623.5 MB/s16 MB/s
SanDisk Ultra 8GB mini class 10 U146 MB/s13.7 MB/s
Adata 8GB class 10 201419.7 MB/s13.2 MB/s
Swissbit 8GB class 623.5 MB/s12.3 MB/s
Sony 8GB class 10 201419.7 MB/s12.3 MB/s
SanDisk Ultra 16GB mini class 1046 MB/s11 MB/s
Adata 8GB class 1020.8 MB/s10.6 MB/s
Sony 8GB SR-8UY class 1057 MB/s9.5 MB/s
LG 2GB class unknown20.9 MB/s8.1 MB/s
Samsung 8GB Class 623.5 MB/s7.7 MB/s
Transcend 2GB class unknown23.5 MB/s7.5 MB/s
Apacer 4GB class 415.4 MB/s3.6 MB/s