Disk /dev/sdc: 16 GB, 16384757760 bytes 255 heads, 63 sectors/track, 1992 cylinders, total 32001480 sectors Units = sectors of 1 * 512 = 512 bytes
Device Boot Start End Blocks Id System /dev/sdc1 * 63 32014079 16008741 b FAT32 Warning: Partition 1 does not end on cylinder boundary.
align 2147483648 pre 505µs on 605µs post 517µs diff 94.4µs align 1073741824 pre 491µs on 600µs post 498µs diff 105µs align 536870912 pre 496µs on 607µs post 489µs diff 115µs align 268435456 pre 506µs on 607µs post 514µs diff 97.3µs align 134217728 pre 527µs on 604µs post 521µs diff 80.6µs align 67108864 pre 492µs on 606µs post 496µs diff 113µs align 33554432 pre 511µs on 607µs post 516µs diff 93.2µs align 16777216 pre 479µs on 592µs post 511µs diff 97.8µs align 8388608 pre 479µs on 479µs post 478µs diff 798ns align 4194304 pre 513µs on 605µs post 494µs diff 101µs align 2097152 pre 558µs on 605µs post 559µs diff 46.6µs align 1048576 pre 474µs on 590µs post 508µs diff 99.7µs align 524288 pre 470µs on 476µs post 474µs diff 3.75µs align 262144 pre 474µs on 480µs post 478µs diff 4.35µs align 131072 pre 473µs on 475µs post 476µs diff 948ns align 65536 pre 474µs on 479µs post 477µs diff 3.13µs align 32768 pre 480µs on 480µs post 477µs diff 1.46µs align 16384 pre 477µs on 481µs post 480µs diff 1.97µs align 8192 pre 475µs on 479µs post 475µs diff 3.88µs align 4096 pre 471µs on 479µs post 477µs diff 5.65µs align 2048 pre 479µs on 483µs post 482µs diff 2.78µs
# linear writing good up to 6x1MB arnd@wuerfel:~/flashbench$ sudo ./flashbench /dev/sdc --blocksize=$[512] --open-au --erasesize=$[1024*1024] --open-au-nr=1 1MiB 28.2M/s 512KiB 28M/s 256KiB 27.2M/s 128KiB 24.9M/s 64KiB 26.7M/s 32KiB 22.2M/s 16KiB 16.7M/s 8KiB 10.4M/s 4KiB 7.45M/s 2KiB 4.14M/s 1KiB 1.44M/s 512B 678K/s arnd@wuerfel:~/flashbench$ sudo ./flashbench /dev/sdc --blocksize=$[512] --open-au --erasesize=$[1024*1024] --open-au-nr=2 1MiB 27.6M/s 512KiB 27.5M/s 256KiB 26.7M/s 128KiB 24.9M/s 64KiB 26M/s 32KiB 21.7M/s 16KiB 16.4M/s 8KiB 10.3M/s 4KiB 7.36M/s 2KiB 4.11M/s 1KiB 1.53M/s 512B 582K/s arnd@wuerfel:~/flashbench$ sudo ./flashbench /dev/sdc --blocksize=4096 --open-au --erasesize=$[1024*1024] --open-au-nr=4 1MiB 21.4M/s 512KiB 27.4M/s 256KiB 26.7M/s 128KiB 24.7M/s 64KiB 26M/s 32KiB 21.8M/s 16KiB 16.4M/s 8KiB 10.1M/s 4KiB 7.28M/s arnd@wuerfel:~/flashbench$ sudo ./flashbench /dev/sdc --blocksize=4096 --open-au --erasesize=$[1024*1024] --open-au-nr=6 1MiB 16.4M/s 512KiB 27.4M/s 256KiB 26.6M/s 128KiB 24.9M/s 64KiB 26.1M/s 32KiB 21.7M/s 16KiB 16.4M/s 8KiB 10.2M/s 4KiB 7.29M/s arnd@wuerfel:~/flashbench$ sudo ./flashbench /dev/sdc --blocksize=4096 --open-au --erasesize=$[1024*1024] --open-au-nr=7 1MiB 27.5M/s 512KiB 16.6M/s 256KiB 7.18M/s 128KiB 3.96M/s 64KiB 2.08M/s 32KiB 1.06M/s 16KiB 527K/s 8KiB 262K/s 4KiB 131K/s
# random writes always bad arnd@wuerfel:~/flashbench$ sudo ./flashbench /dev/sdc --blocksize=4096 --open-au --erasesize=$[1024*1024] --open-au-nr=1 --random 1MiB 25.6M/s 512KiB 10.3M/s 256KiB 18.8M/s 128KiB 8.1M/s 64KiB 3.37M/s 32KiB 1.74M/s 16KiB 888K/s 8KiB 437K/s 4KiB 215K/s
# at least 1 MB erase block, seen from lower throughput at 512KB arnd@wuerfel:~/flashbench$ sudo ./flashbench /dev/sdc --blocksize=4096 --open-au --erasesize=$[512*1024] --open-au-nr=6 512KiB 17.1M/s 256KiB 16M/s 128KiB 15.2M/s 64KiB 12.5M/s 32KiB 14.1M/s 16KiB 11.6M/s 8KiB 8.07M/s 4KiB 6.09M/s
# no special FAT area! arnd@wuerfel:~/flashbench$ sudo ./flashbench /dev/sdc --blocksize=4096 --erasesize=$[1024*1024] --findfat --fat-nr=6 1MiB 28.5M/s 26.1M/s 27.6M/s 26.6M/s 28.4M/s 26.1M/s 512KiB 27.4M/s 25.9M/s 26.8M/s 26.3M/s 27.8M/s 25.8M/s 256KiB 27.3M/s 25.3M/s 26.4M/s 25.6M/s 27.3M/s 25.2M/s 128KiB 25.4M/s 23.4M/s 25M/s 23.8M/s 25.3M/s 23.4M/s 64KiB 26.7M/s 24.8M/s 25.4M/s 24.7M/s 26.7M/s 24.8M/s 32KiB 22.3M/s 20.8M/s 21.6M/s 21.1M/s 22M/s 20.9M/s 16KiB 16.8M/s 16M/s 16.2M/s 16.1M/s 16.7M/s 15.9M/s 8KiB 10.3M/s 9.77M/s 10.3M/s 10.2M/s 10.4M/s 9.78M/s 4KiB 7.45M/s 6.9M/s 7.24M/s 7.27M/s 7.49M/s 6.89M/s
arnd@wuerfel:~/flashbench$ sudo ./flashbench /dev/sdc --blocksize=4096 --erasesize=$[1024*1024] --findfat --fat-nr=6 --random 1MiB 28.5M/s 26M/s 27.6M/s 26.5M/s 27.9M/s 26.2M/s 512KiB 21.1M/s 19.5M/s 20.5M/s 19.5M/s 21.2M/s 19.3M/s 256KiB 18.9M/s 17.3M/s 12.5M/s 17.5M/s 18.9M/s 17.2M/s 128KiB 8.05M/s 7.23M/s 7.65M/s 4.81M/s 5.37M/s 7.23M/s 64KiB 3.32M/s 3.09M/s 4.44M/s 4.37M/s 4.77M/s 3.09M/s 32KiB 1.84M/s 1.63M/s 1.49M/s 1.68M/s 1.56M/s 1.63M/s 16KiB 874K/s 743K/s 824K/s 740K/s 872K/s 789K/s 8KiB 455K/s 395K/s 414K/s 408K/s 435K/s 391K/s