[Flashbench] flashbench result for SanDisk 31166976 KB SDHC Class4 MMC card

[Amit Pundir]

$ sudo ./flashbench -a /dev/mmcblk0 --blocksize=$[4 * 1024]
align 8589934592        pre 4.43ms      on 4.48ms       post 3.9ms
 diff 320µs
align 4294967296        pre 4.56ms      on 4.62ms       post 4.01ms
 diff 332µs
align 2147483648        pre 4.21ms      on 4.45ms       post 3.87ms
 diff 405µs
align 1073741824        pre 4.56ms      on 4.59ms       post 3.97ms
 diff 327µs
align 536870912 pre 4.54ms      on 4.5ms        post 3.86ms     diff 303µs
align 268435456 pre 4.49ms      on 4.56ms       post 3.95ms     diff 333µs
align 134217728 pre 4.17ms      on 4.48ms       post 3.87ms     diff 459µs
align 67108864  pre 4.58ms      on 4.61ms       post 3.93ms     diff 357µs
align 33554432  pre 4.02ms      on 4.22ms       post 3.5ms      diff 464µs
align 16777216  pre 4.16ms      on 4.22ms       post 3.55ms     diff 367µs
align 8388608   pre 4.25ms      on 4.2ms        post 3.47ms     diff 345µs
align 4194304   pre 4.16ms      on 4.25ms       post 3.51ms     diff 411µs
align 2097152   pre 4.27ms      on 4.24ms       post 3.54ms     diff 340µs
align 1048576   pre 4.21ms      on 4.32ms       post 3.56ms     diff 430µs
align 524288    pre 4.18ms      on 4.26ms       post 3.49ms     diff 427µs
align 262144    pre 3.54ms      on 3.58ms       post 3.56ms     diff 32.1µs
align 131072    pre 3.62ms      on 3.61ms       post 3.54ms     diff 29.9µs
align 65536     pre 3.44ms      on 3.63ms       post 3.53ms     diff 146µs
align 32768     pre 3.55ms      on 3.57ms       post 3.5ms      diff 48µs
align 16384     pre 3.44ms      on 3.62ms       post 3.59ms     diff 102µs
align 8192      pre 3.62ms      on 3.57ms       post 3.52ms     diff 4.96µs

Erase Block size found to be 512KB which is kind of surprising because
possibility of a 512KB erase block size is not there in your LWN
article. Anyways moving on..

$ sudo ./flashbench -O --erasesize=$[512 * 1024] --blocksize=$[4 *
1024] /dev/mmcblk0 --open-au --random
512KiB  6.14M/s
256KiB  6.39M/s
128KiB  6.3M/s
64KiB   6.16M/s
32KiB   5.75M/s
16KiB   4.64M/s
8KiB    3.39M/s
4KiB    2.23M/s

$ sudo ./flashbench -O --erasesize=$[512 * 1024] --blocksize=$[4 *
1024] /dev/mmcblk0 --open-au
512KiB  6.14M/s
256KiB  6.36M/s
128KiB  6.25M/s
64KiB   6.14M/s
32KiB   3.79M/s
16KiB   3.45M/s
8KiB    3.44M/s
4KiB    2.28M/s

$ sudo ./flashbench -O --erasesize=$[512 * 1024] --blocksize=$[4 *
1024] /dev/mmcblk0 --open-au-nr=1 --random
512KiB  5.68M/s
256KiB  6.22M/s
128KiB  6.33M/s
64KiB   6.29M/s
32KiB   5.93M/s
16KiB   4.9M/s
8KiB    3.3M/s
4KiB    2.19M/s

$ sudo ./flashbench -O --erasesize=$[512 * 1024] --blocksize=$[4 *
1024] /dev/mmcblk0 --open-au-nr=1
512KiB  6.06M/s
256KiB  6.4M/s
128KiB  6.34M/s
64KiB   6.35M/s
32KiB   4.05M/s
16KiB   4.25M/s
8KiB    5.18M/s
4KiB    3.92M/s

Got consistent numbers till open erase block = 17 but beyond that also
numbers are not that bad as well.

$ sudo ./flashbench -O --erasesize=$[512 * 1024] --blocksize=$[4 *
1024] /dev/mmcblk0 --open-au-nr=17 --random
512KiB  5.95M/s
256KiB  5.14M/s
128KiB  4.64M/s
64KiB   5.83M/s
32KiB   5.76M/s
16KiB   4.64M/s
8KiB    2.92M/s
4KiB    2.23M/s

$ sudo ./flashbench -O --erasesize=$[512 * 1024] --blocksize=$[4 *
1024] /dev/mmcblk0 --open-au-nr=17
512KiB  6.38M/s
256KiB  6.04M/s
128KiB  6.17M/s
64KiB   5.22M/s
32KiB   4.4M/s
16KiB   4.51M/s
8KiB    2.77M/s
4KiB    2.13M/s

$ sudo ./flashbench -O --erasesize=$[512 * 1024] --blocksize=$[4 *
1024] /dev/mmcblk0 --open-au-nr=18 --random
512KiB  4.27M/s
256KiB  4.54M/s
128KiB  4.12M/s
64KiB   4.53M/s
32KiB   4.36M/s
16KiB   2.71M/s
8KiB    1.35M/s
4KiB    1.5M/s

$ sudo ./flashbench -O --erasesize=$[512 * 1024] --blocksize=$[4 *
1024] /dev/mmcblk0 --open-au-nr=18
512KiB  6.34M/s
256KiB  5.22M/s
128KiB  5.37M/s
64KiB   4.88M/s
32KiB   5.16M/s
16KiB   3.79M/s
8KiB    3.05M/s
4KiB    2.14M/s