Transcend 4GB class6
Size: 3905536
/sys/devices/pci0000:00/0000:00:0c.0/mmc_host/mmc2/mmc2:8c10/name SU04G
/sys/block/mmcblk0/device/
name SDC
oemid 0x5356, 
manfid 0x00001c, 
hwrev 0x1, 
fwrev 0x0, serial 
0x05593bca, 
scr 0235000000000000, 
csd 400e00325f5900001dcb7f800a400000

bash-4.1# ./flashbench -a /dev/mmcblk0  --blocksize=1024
align 1073741824	pre 604µs	on 669µs	post 576µs	diff 79.1µs
align 536870912	pre 586µs	on 658µs	post 568µs	diff 81.3µs
align 268435456	pre 579µs	on 658µs	post 567µs	diff 85.1µs
align 134217728	pre 585µs	on 655µs	post 563µs	diff 81.3µs
align 67108864	pre 582µs	on 661µs	post 554µs	diff 92.6µs
align 33554432	pre 582µs	on 653µs	post 563µs	diff 80.6µs
align 16777216	pre 587µs	on 660µs	post 562µs	diff 85.5µs
align 8388608	pre 584µs	on 669µs	post 566µs	diff 93.7µs
align 4194304	pre 589µs	on 664µs	post 567µs	diff 86.6µs
align 2097152	pre 585µs	on 659µs	post 569µs	diff 81.3µs

align 1048576	pre 588µs	on 643µs	post 594µs	diff 52.2µs
align 524288	pre 588µs	on 640µs	post 584µs	diff 54.3µs
align 262144	pre 580µs	on 638µs	post 587µs	diff 54.4µs
align 131072	pre 584µs	on 635µs	post 586µs	diff 49.9µs
align 65536	pre 594µs	on 635µs	post 588µs	diff 43.8µs
align 32768	pre 571µs	on 614µs	post 563µs	diff 46.9µs
align 16384	pre 574µs	on 609µs	post 565µs	diff 39.6µs
align 8192	pre 572µs	on 614µs	post 562µs	diff 46.9µs
align 4096	pre 573µs	on 610µs	post 565µs	diff 41.3µs

align 2048	pre 560µs	on 564µs	post 558µs	diff 5.55µs


bash-4.1# ./flashbench -O --erasesize=$[2 * 1024 * 1024] --blocksize=$[16 * 1024] /dev/mmcblk0 --open-au-nr=4
2MiB    9.38M/s 
1MiB    8.67M/s 
512KiB  8.88M/s 
256KiB  8.49M/s 
128KiB  8.63M/s 
64KiB   9.83M/s 
32KiB   10.6M/s 
16KiB   8.59M/s 
bash-4.1# ./flashbench -O --erasesize=$[2 * 1024 * 1024] --blocksize=$[16 * 1024] /dev/mmcblk0 --open-au-nr=5
2MiB    9.96M/s 
1MiB    9.28M/s 
512KiB  9.5M/s  
256KiB  9.06M/s 
128KiB  9.22M/s 
64KiB   10.2M/s 
32KiB   10.5M/s 
16KiB   8.7M/s 
bash-4.1# ./flashbench -O --erasesize=$[2 * 1024 * 1024] --blocksize=$[16 * 1024] /dev/mmcblk0 --open-au-nr=6
2MiB    6.65M/s 
1MiB    5.93M/s 
512KiB  2.45M/s 
256KiB  1.35M/s 
128KiB  720K/s  
64KiB   381K/s  
32KiB   194K/s  
16KiB   97.6K/s

bash-4.1# ./flashbench -O --erasesize=$[2 * 1024 * 1024] --blocksize=$[16 * 1024] /dev/mmcblk0  --random --open-au-nr=4
2MiB    5.96M/s 
1MiB    5.55M/s 
512KiB  5.1M/s  
256KiB  4.91M/s 
128KiB  4.8M/s  
64KiB   4.75M/s 
32KiB   4.09M/s 
16KiB   3.3M/s  
bash-4.1# ./flashbench -O --erasesize=$[2 * 1024 * 1024] --blocksize=$[16 * 1024] /dev/mmcblk0  --random --open-au-nr=5
2MiB    6.05M/s 
1MiB    5.61M/s 
512KiB  5.12M/s 
256KiB  4.91M/s 
128KiB  4.8M/s  
64KiB   4.7M/s  
32KiB   4.11M/s 
16KiB   3.28M/s 
bash-4.1# ./flashbench -O --erasesize=$[2 * 1024 * 1024] --blocksize=$[4 * 1024] /dev/mmcblk0  --random --open-au-nr=6
2MiB    7.97M/s 
1MiB    4.28M/s 
512KiB  2.52M/s 
256KiB  1.36M/s 
128KiB  722K/s  
64KiB   378K/s  
32KiB   193K/s
16KiB   97.5K/s

bash-4.1# ./flashbench --erasesize=$[2 * 1024 * 1024] --findfat --random /dev/mmcblk0
2MiB    5M/s     7.62M/s  7.14M/s  12.6M/s  12.5M/s  12.3M/s  
1MiB    4.78M/s  4.85M/s  4.82M/s  3.46M/s  3.47M/s  3.52M/s  
512KiB  3.52M/s  3.54M/s  3.53M/s  3.53M/s  3.53M/s  3.48M/s  
256KiB  3.52M/s  3.49M/s  3.49M/s  3.42M/s  3.47M/s  3.5M/s   
128KiB  3.5M/s   3.5M/s   3.51M/s  3.5M/s   3.51M/s  3.5M/s   
64KiB   3.46M/s  3.43M/s  3.48M/s  3.49M/s  3.46M/s  3.47M/s  
32KiB   3.16M/s  3.17M/s  3.13M/s  3.13M/s  3.16M/s  3.14M/s  
16KiB   2.64M/s  2.65M/s  2.66M/s  2.63M/s  2.65M/s  2.65M/s