andrew@piglet:~/git/flashbench$ head /sys/block/mmcblk0/device/* 2>/dev/null | grep -v ^$ ==> /sys/block/mmcblk0/device/block <== ==> /sys/block/mmcblk0/device/cid <== 0353445343313238805bd83d89011a00 ==> /sys/block/mmcblk0/device/csd <== 400e00325b590003b8ab7f800a404000 ==> /sys/block/mmcblk0/device/date <== 10/2017 ==> /sys/block/mmcblk0/device/driver <== ==> /sys/block/mmcblk0/device/dsr <== 0x404 ==> /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 <== SC128 ==> /sys/block/mmcblk0/device/ocr <== 00200000 ==> /sys/block/mmcblk0/device/oemid <== 0x5344 ==> /sys/block/mmcblk0/device/power <== ==> /sys/block/mmcblk0/device/preferred_erase_size <== 4194304 ==> /sys/block/mmcblk0/device/scr <== 0245804300000000 ==> /sys/block/mmcblk0/device/serial <== 0x5bd83d89 ==> /sys/block/mmcblk0/device/ssr <== 0000000008000000040090000f051a00000000000001000000000000000000000000000000000000000000000000000000000000000000000000000000000000 ==> /sys/block/mmcblk0/device/subsystem <== ==> /sys/block/mmcblk0/device/type <== SD ==> /sys/block/mmcblk0/device/uevent <== DRIVER=mmcblk MMC_TYPE=SD MMC_NAME=SC128 MODALIAS=mmc:block

andrew@piglet:~/git/flashbench$ sudo fdisk -l /dev/mmcblk0 Disk /dev/mmcblk0: 119.1 GiB, 127865454592 bytes, 249737216 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 Disklabel type: dos Disk identifier: 0x00000000

Device Boot Start End Sectors Size Id Type /dev/mmcblk0p1 32768 249737215 249704448 119.1G 7 HPFS/NTFS/exFAT

andrew@piglet:~/git/flashbench$ sudo ./flashbench -a /dev/mmcblk0 --blocksize=4096 --count=100 align 34359738368 pre 478µs on 525µs post 476µs diff 48.1µs align 17179869184 pre 479µs on 544µs post 475µs diff 66.7µs align 8589934592 pre 476µs on 550µs post 480µs diff 71.6µs align 4294967296 pre 460µs on 531µs post 459µs diff 71.8µs align 2147483648 pre 449µs on 449µs post 449µs diff -263ns align 1073741824 pre 463µs on 463µs post 463µs diff -251ns align 536870912 pre 452µs on 452µs post 452µs diff -433ns align 268435456 pre 460µs on 458µs post 459µs diff -957ns align 134217728 pre 459µs on 462µs post 459µs diff 3.32µs align 67108864 pre 460µs on 462µs post 459µs diff 2.07µs align 33554432 pre 480µs on 481µs post 472µs diff 5.19µs align 16777216 pre 473µs on 477µs post 469µs diff 5.78µs align 8388608 pre 498µs on 502µs post 494µs diff 5.79µs align 4194304 pre 494µs on 501µs post 494µs diff 7.02µs align 2097152 pre 478µs on 486µs post 486µs diff 3.95µs align 1048576 pre 487µs on 486µs post 485µs diff 412ns align 524288 pre 474µs on 472µs post 482µs diff -5881ns align 262144 pre 471µs on 471µs post 476µs diff -2147ns align 131072 pre 497µs on 497µs post 490µs diff 3.51µs align 65536 pre 488µs on 483µs post 489µs diff -5657ns align 32768 pre 488µs on 491µs post 489µs diff 2.71µs align 16384 pre 477µs on 477µs post 475µs diff 398ns align 8192 pre 494µs on 494µs post 495µs diff 46ns

# Maybe 2 MiB erase blocks? But this seems unlikely for the size of this # card. More likely something larger I assume, I use 8 MiB for my # tests.

andrew@piglet:~/git/flashbench$ sudo ./flashbench /dev/mmcblk0 --open-au --erasesize=$[8*1024*1024] --blocksize=$[8*1024] --open-au-nr=1 8MiB 17.9M/s 4MiB 17.1M/s 2MiB 17.6M/s 1MiB 17.8M/s 512KiB 17.5M/s 256KiB 17.3M/s 128KiB 17.2M/s 64KiB 14.8M/s 32KiB 13.5M/s 16KiB 10.1M/s 8KiB 6.49M/s

andrew@piglet:~/git/flashbench$ sudo ./flashbench /dev/mmcblk0 --open-au --erasesize=$[8*1024*1024] --blocksize=$[8*1024] --open-au-nr=20 8MiB 14.3M/s 4MiB 15.5M/s 2MiB 16.2M/s 1MiB 16.2M/s 512KiB 16M/s 256KiB 15.9M/s 128KiB 15.1M/s 64KiB 15.1M/s 32KiB 12.5M/s 16KiB 9.36M/s 8KiB 6.58M/s

# Can do lots of open-au

andrew@piglet:~/git/flashbench$ sudo ./flashbench /dev/mmcblk0 --open-au --erasesize=$[8*1024*1024] --blocksize=$[8*1024] --open-au-nr=20 --random 8MiB 15.2M/s 4MiB 11.5M/s 2MiB 15.5M/s 1MiB 15.1M/s 512KiB 16.2M/s 256KiB 15M/s 128KiB 14.6M/s 64KiB 15.3M/s 32KiB 12.2M/s 16KiB 8.43M/s 8KiB 6.06M/s

# And good random performance, too. Although my open-au tests may show # better than they should if I have the erase block size really wrong, # but I expected the random would expose that somewhat.

Overall a pretty decent seeming card I think. Thanks, Andrew