$ head /sys/block/mmcblk0/device/{c*,scr,*rev,*id,serial,*size,name,date} ==> /sys/block/mmcblk0/device/cid <== 02544d534130324705200a985700a700 ==> /sys/block/mmcblk0/device/csd <== 002e00325b5aa3acffffff800a800000 ==> /sys/block/mmcblk0/device/scr <== 0225800001000000 ==> /sys/block/mmcblk0/device/fwrev <== 0x5 ==> /sys/block/mmcblk0/device/hwrev <== 0x0 ==> /sys/block/mmcblk0/device/cid <== 02544d534130324705200a985700a700 ==> /sys/block/mmcblk0/device/manfid <== 0x000002 ==> /sys/block/mmcblk0/device/oemid <== 0x544d ==> /sys/block/mmcblk0/device/serial <== 0x200a9857 ==> /sys/block/mmcblk0/device/erase_size <== 512 ==> /sys/block/mmcblk0/device/preferred_erase_size <== 4194304 ==> /sys/block/mmcblk0/device/name <== SA02G ==> /sys/block/mmcblk0/device/date <== 07/2010

$ sudo ./flashbench -a /dev/mmcblk0 --blocksize 1024 --count=50 [sudo] password for arnd: align 268435456 pre 1.45ms on 2.14ms post 1.19ms diff 819µs align 134217728 pre 1.77ms on 2.39ms post 1.26ms diff 874µs align 67108864 pre 1.78ms on 2.16ms post 1.19ms diff 677µs align 33554432 pre 1.77ms on 2.17ms post 1.21ms diff 680µs align 16777216 pre 1.58ms on 2.18ms post 1.21ms diff 788µs align 8388608 pre 1.26ms on 2.13ms post 1.21ms diff 900µs align 4194304 pre 1.3ms on 2.16ms post 1.21ms diff 911µs align 2097152 pre 1.5ms on 2.16ms post 1.18ms diff 822µs align 1048576 pre 1.21ms on 1.41ms post 1.24ms diff 186µs align 524288 pre 1.21ms on 1.27ms post 1.21ms diff 60.4µs align 262144 pre 1.21ms on 1.27ms post 1.21ms diff 59.3µs align 131072 pre 1.21ms on 1.27ms post 1.21ms diff 59.2µs align 65536 pre 1.21ms on 1.27ms post 1.21ms diff 59.2µs align 32768 pre 1.21ms on 1.27ms post 1.21ms diff 60.3µs align 16384 pre 1.22ms on 1.27ms post 1.21ms diff 57.8µs align 8192 pre 1.21ms on 1.28ms post 1.21ms diff 61.7µs align 4096 pre 1.21ms on 1.26ms post 1.21ms diff 41.6µs align 2048 pre 1.21ms on 1.26ms post 1.21ms diff 41.1µs

$ sudo ./flashbench --findfat --fat-nr=4 /dev/mmcblk0 --blocksize=1024 --erasesize=$[2* 1024 * 1024] 2MiB 2.33M/s 4.67M/s 9.32M/s 9.57M/s 1MiB 3.4M/s 9.49M/s 9.31M/s 9.59M/s 512KiB 3.41M/s 9.54M/s 9.57M/s 9.51M/s 256KiB 4.95M/s 9.73M/s 9.63M/s 9.62M/s 128KiB 5.79M/s 9.76M/s 9.64M/s 9.72M/s 64KiB 6.04M/s 9.59M/s 9.9M/s 9.85M/s 32KiB 4.35M/s 8.92M/s 8.82M/s 8.87M/s 16KiB 2.98M/s 7.23M/s 7.25M/s 7.31M/s 8KiB 1.68M/s 4.67M/s 4.59M/s 4.62M/s 4KiB 847K/s 1.45M/s 1.56M/s 1.55M/s 2KiB 431K/s 726K/s 715K/s 736K/s 1KiB 218K/s 137K/s 137K/s 126K/s

$ sudo ./flashbench --findfat --fat-nr=4 /dev/mmcblk0 --blocksize=4096 --erasesize=$[2* 1024 * 1024] --random 2MiB 2.3M/s 9.48M/s 9.29M/s 9.22M/s 1MiB 3.42M/s 5.89M/s 3.01M/s 3M/s 512KiB 4.51M/s 2.03M/s 1.85M/s 1.82M/s 256KiB 4.89M/s 1.32M/s 1.31M/s 1.31M/s 128KiB 4.93M/s 696K/s 696K/s 694K/s 64KiB 5.58M/s 850K/s 853K/s 849K/s 32KiB 4.56M/s 325K/s 326K/s 327K/s ^C

$ sudo ./flashbench --open-au --open-au-nr=1 /dev/mmcblk0 --erasesize=$[2 * 1024 * 1024] --blocksize=1024 2MiB 8.25M/s 1MiB 2.65M/s 512KiB 2.67M/s 256KiB 2.67M/s 128KiB 4.16M/s 64KiB 9.48M/s 32KiB 8.56M/s 16KiB 6.59M/s 8KiB 4M/s 4KiB 1.32M/s 2KiB 544K/s 1KiB 14.1K/s (!!!)

$ sudo ./flashbench --open-au --open-au-nr=1 /dev/mmcblk0 --erasesize=$[4 * 1024 * 1024] --blocksize=1024 4MiB 9.37M/s 2MiB 4.17M/s 1MiB 4.17M/s 512KiB 4.17M/s 256KiB 4.17M/s 128KiB 5.8M/s 64KiB 9.54M/s 32KiB 8.47M/s 16KiB 6.5M/s 8KiB 3.94M/s 4KiB 1.26M/s 2KiB 538K/s ^C

$ sudo ./flashbench --open-au --open-au-nr=2 /dev/mmcblk0 --erasesize=$[2 * 1024 * 1024] --blocksize=1024 2MiB 5.82M/s 1MiB 3.62M/s 512KiB 1.43M/s 256KiB 658K/s 128KiB 318K/s 64KiB 232K/s ^C

$ sudo ./flashbench --open-au --open-au-nr=2 /dev/mmcblk0 --erasesize=$[4 * 1024 * 1024] --blocksize=1024 4MiB 8.52M/s 2MiB 5.78M/s 1MiB 2.79M/s 512KiB 1.34M/s 256KiB 639K/s 128KiB 314K/s 64KiB 233K/s 32KiB 116K/s ^C