Hi there, I tested a brandnew 8GB SanDisk Extreme SDHC, class 10.

erase block size: 4MB block size: ?? open erase blocks: 6

Bye, Holger

==> /sys/block/mmcblk0/device/block <== ==> /sys/block/mmcblk0/device/cid <== 035344534430384780310a033a00c100 ==> /sys/block/mmcblk0/device/csd <== 400e00325b5900003b377f800a404000 ==> /sys/block/mmcblk0/device/date <== 01/2012 ==> /sys/block/mmcblk0/device/driver <== ==> /sys/block/mmcblk0/device/erase_size <== 512 ==> /sys/block/mmcblk0/device/fwrev <== 0x0 ==> /sys/block/mmcblk0/device/hwrev <== 0x8 ==> /sys/block/mmcblk0/device/manfid <== 0x000003 ==> /sys/block/mmcblk0/device/name <== SD08G ==> /sys/block/mmcblk0/device/oemid <== 0x5344 ==> /sys/block/mmcblk0/device/power <== ==> /sys/block/mmcblk0/device/preferred_erase_size <== 4194304 ==> /sys/block/mmcblk0/device/scr <== 0235800100000000 ==> /sys/block/mmcblk0/device/serial <== 0x310a033a ==> /sys/block/mmcblk0/device/subsystem <== ==> /sys/block/mmcblk0/device/type <== SD ==> /sys/block/mmcblk0/device/uevent <== DRIVER=mmcblk MMC_TYPE=SD MMC_NAME=SD08G MODALIAS=mmc:block

Original partition table:

Disk /dev/sdd: 7948 MB, 7948206080 bytes 81 heads, 10 sectors/track, 19165 cylinders, total 15523840 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00000000

Device Boot      Start         End      Blocks   Id  System /dev/sdd1            8192    15523839     7757824    b  W95 FAT32

./flashbench -a /dev/sdc --blocksize=1024 align 2147483648        pre 1.06ms      on 1.41ms       post 1.13ms     diff 317µs align 1073741824        pre 1.02ms      on 1.39ms       post 1.14ms     diff 308µs align 536870912 pre 937µs       on 1.36ms       post 1.03ms     diff  377µs align 268435456 pre 1.05ms      on 1.4ms        post 1.12ms     diff 310µs align 134217728 pre 1.04ms      on 1.41ms       post 1.12ms     diff 332µs align 67108864  pre 1.02ms      on 1.38ms       post 1.12ms     diff 312µs align 33554432  pre 1.01ms      on 1.43ms       post 1.11ms     diff 373µs align 16777216  pre 1.03ms      on 1.4ms        post 1.09ms     diff 343µs align 8388608   pre 1.15ms      on 1.57ms       post 1.08ms     diff 451µs align 4194304   pre 1.33ms      on 1.73ms       post 1.33ms     diff 396µs align 2097152   pre 1.2ms       on 1.21ms       post 1.22ms     diff 1.92µs align 1048576   pre 1.21ms      on 1.22ms       post 1.21ms     diff 8.04µs align 524288    pre 1.2ms       on 1.24ms       post 1.22ms     diff 30.4µs align 262144    pre 1.21ms      on 1.22ms       post 1.23ms     diff 1.48µs align 131072    pre 1.21ms      on 1.23ms       post 1.22ms     diff 9.99µs align 65536     pre 1.2ms       on 1.22ms       post 1.21ms     diff 9.37µs align 32768     pre 1.21ms      on 1.23ms       post 1.2ms      diff 25.5µs align 16384     pre 1.22ms      on 1.23ms       post 1.21ms     diff 14.3µs align 8192      pre 1.22ms      on 1.21ms       post 1.22ms     diff -10224n align 4096      pre 1.2ms       on 1.2ms        post 1.2ms      diff 2.93µs align 2048      pre 1.22ms      on 1.21ms       post 1.23ms     diff -16677n

RANDOM TESTS ./flashbench /dev/sdc --open-au --erasesize=4194304 --blocksize=4096 --open-au-nr=1 --random 4MiB    20.5M/s 2MiB    20.3M/s 1MiB    19.8M/s 512KiB  6.35M/s 256KiB  2.37M/s 128KiB  1.16M/s 64KiB   662K/s   32KiB   312K/s   16KiB   257K/s   8KiB    1.66M/s 4KiB    913K/s   ./flashbench /dev/sdc --open-au --erasesize=4194304 --blocksize=4096 --open-au-nr=2 --random 4MiB    20.2M/s 2MiB    20.3M/s 1MiB    20M/s   512KiB  6.43M/s 256KiB  2.38M/s 128KiB  1.16M/s 64KiB   662K/s   32KiB   312K/s   16KiB   236K/s   8KiB    1.61M/s 4KiB    880K/s   ./flashbench /dev/sdc --open-au --erasesize=4194304 --blocksize=4096 --open-au-nr=3 --random 4MiB    20.2M/s 2MiB    20M/s   1MiB    19.9M/s 512KiB  6.45M/s 256KiB  2.37M/s 128KiB  1.16M/s 64KiB   662K/s   32KiB   313K/s   16KiB   254K/s   8KiB    1.58M/s 4KiB    865K/s   ./flashbench /dev/sdc --open-au --erasesize=4194304 --blocksize=4096 --open-au-nr=4 --random 4MiB    20.4M/s 2MiB    20.3M/s 1MiB    20.1M/s 512KiB  6.38M/s 256KiB  2.38M/s 128KiB  1.16M/s 64KiB   662K/s   32KiB   312K/s   16KiB   245K/s   8KiB    1.58M/s 4KiB    864K/s   ./flashbench /dev/sdc --open-au --erasesize=4194304 --blocksize=4096 --open-au-nr=5 --random 4MiB    20.4M/s 2MiB    20.2M/s 1MiB    20.2M/s 512KiB  6.44M/s 256KiB  2.37M/s 128KiB  1.16M/s 64KiB   662K/s   32KiB   312K/s   16KiB   264K/s   8KiB    1.58M/s 4KiB    864K/s   ./flashbench /dev/sdc --open-au --erasesize=4194304 --blocksize=4096 --open-au-nr=6 --random 4MiB    20.4M/s 2MiB    20.2M/s 1MiB    20.1M/s 512KiB  6.38M/s 256KiB  2.37M/s 128KiB  1.16M/s 64KiB   662K/s   32KiB   312K/s   16KiB   241K/s   8KiB    1.52M/s 4KiB    856K/s ./flashbench /dev/sdc --open-au --erasesize=4194304 --blocksize=4096 --open-au-nr=7 --random 4MiB    20.4M/s 2MiB    11.1M/s 1MiB    4.4M/s   512KiB  2.06M/s 256KiB  2.24M/s 128KiB  1.15M/s 64KiB   661K/s   32KiB   311K/s   16KiB   259K/s   8KiB    1.45M/s 4KiB    858K/s   ./flashbench /dev/sdc --open-au --erasesize=4194304 --blocksize=4096 --open-au-nr=8 --random 4MiB    20.4M/s 2MiB    11.2M/s 1MiB    4.37M/s 512KiB  2.05M/s 256KiB  1.01M/s 128KiB  499K/s   64KiB   249K/s   32KiB   125K/s   16KiB   278K/s   8KiB    1.4M/s   4KiB    862K/s

LINEAR TESTS ./flashbench /dev/sdc --open-au --erasesize=4194304 --blocksize=4096 --open-au-nr=1 4MiB    20.2M/s 2MiB    20.3M/s 1MiB    20.4M/s 512KiB  20.3M/s 256KiB  20M/s   128KiB  19.1M/s 64KiB   19.2M/s 32KiB   16.9M/s 16KiB   13.9M/s 8KiB    9.94M/s 4KiB    7.07M/s ./flashbench /dev/sdc --open-au --erasesize=4194304 --blocksize=4096 --open-au-nr=2 4MiB    20.6M/s 2MiB    20.4M/s 1MiB    20.1M/s 512KiB  19.7M/s 256KiB  18.6M/s 128KiB  17M/s   64KiB   18M/s   32KiB   12.5M/s 16KiB   8.61M/s 8KiB    4.42M/s 4KiB    2.01M/s ./flashbench /dev/sdc --open-au --erasesize=4194304 --blocksize=4096 --open-au-nr=3 4MiB    20.5M/s 2MiB    20M/s   1MiB    20.2M/s 512KiB  19.6M/s 256KiB  18.6M/s 128KiB  16.9M/s 64KiB   18M/s   32KiB   12.4M/s 16KiB   8.5M/s   8KiB    3.97M/s 4KiB    1.98M/s ./flashbench /dev/sdc --open-au --erasesize=4194304 --blocksize=4096 --open-au-nr=4 4MiB    20.5M/s 2MiB    20.3M/s 1MiB    20M/s   512KiB  19.6M/s 256KiB  18.5M/s 128KiB  16.9M/s 64KiB   18M/s   32KiB   12.3M/s 16KiB   8.54M/s 8KiB    4.38M/s 4KiB    1.97M/s ./flashbench /dev/sdc --open-au --erasesize=4194304 --blocksize=4096 --open-au-nr=5 4MiB    20.5M/s 2MiB    20.2M/s 1MiB    20M/s   512KiB  19.6M/s 256KiB  18.5M/s 128KiB  16.9M/s 64KiB   18M/s   32KiB   12.4M/s 16KiB   8.52M/s 8KiB    4.11M/s 4KiB    1.96M/s ./flashbench /dev/sdc --open-au --erasesize=4194304 --blocksize=4096 --open-au-nr=6 4MiB    20.6M/s 2MiB    20.3M/s 1MiB    20.1M/s 512KiB  19.6M/s 256KiB  18.6M/s 128KiB  16.9M/s 64KiB   17.9M/s 32KiB   12.3M/s 16KiB   8.48M/s 8KiB    4.13M/s 4KiB    2.04M/s ./flashbench /dev/sdc --open-au --erasesize=4194304 --blocksize=4096 --open-au-nr=7 4MiB    20.3M/s 2MiB    11.5M/s 1MiB    4.41M/s 512KiB  2.06M/s 256KiB  9.22M/s 128KiB  16.9M/s 64KiB   18.1M/s 32KiB   12.3M/s 16KiB   8.48M/s 8KiB    4.16M/s 4KiB    1.95M/s ./flashbench /dev/sdc --open-au --erasesize=4194304 --blocksize=4096 --open-au-nr=8 4MiB    20.4M/s 2MiB    11.7M/s 1MiB    4.4M/s   512KiB  2.06M/s 256KiB  1.01M/s 128KiB  499K/s   64KiB   249K/s   32KiB   125K/s   16KiB   973K/s   8KiB    453K/s   4KiB    411K/s

./flashbench /dev/sdc -f --erasesize=4194304 4MiB    19.7M/s  18.9M/s  20.3M/s  20.4M/s  20M/s    20.3M/s   2MiB    20.5M/s  18.9M/s  19.8M/s  20.6M/s  20.2M/s  20.6M/s   1MiB    20.4M/s  19M/s    20.1M/s  20.2M/s  20.5M/s  20.2M/s   512KiB  20.3M/s  19.2M/s  19.8M/s  20.2M/s  20.2M/s  20.2M/s   256KiB  19.9M/s  18.9M/s  19.4M/s  19.8M/s  19.6M/s  19.6M/s   128KiB  19M/s    17.9M/s  18.7M/s  18.9M/s  19.1M/s  18.8M/s   64KiB   18.9M/s  17.9M/s  18.2M/s  18.9M/s  18.9M/s  18.9M/s   32KiB   16.7M/s  15.9M/s  16.5M/s  16.6M/s  16.5M/s  16.5M/s   16KiB   13.8M/s  13.1M/s  13.9M/s  13.6M/s  13.7M/s  13.6M/s