Flashbench results for Micron MTFC2GMVEA-0M WT 2GB eMMC.
root@beaglebone:~/flashbench# head /sys/block/mmcblk1/device/* 2>/dev/null | grep -v ^$ ==> /sys/block/mmcblk1/device/block <== ==> /sys/block/mmcblk1/device/cid <== fe014e4d4d433032473a1158f1467f35 ==> /sys/block/mmcblk1/device/csd <== d04f01320f5a1393ffffffe38a4000e7 ==> /sys/block/mmcblk1/device/date <== 07/2012 ==> /sys/block/mmcblk1/device/driver <== ==> /sys/block/mmcblk1/device/enhanced_area_offset <== 18446744073709551594 ==> /sys/block/mmcblk1/device/enhanced_area_size <== 4294967274 ==> /sys/block/mmcblk1/device/erase_size <== 524288 ==> /sys/block/mmcblk1/device/fwrev <== 0x0 ==> /sys/block/mmcblk1/device/hwrev <== 0x0 ==> /sys/block/mmcblk1/device/manfid <== 0x0000fe ==> /sys/block/mmcblk1/device/name <== MMC02G ==> /sys/block/mmcblk1/device/oemid <== 0x014e ==> /sys/block/mmcblk1/device/power <== ==> /sys/block/mmcblk1/device/preferred_erase_size <== 4194304 ==> /sys/block/mmcblk1/device/raw_rpmb_size_mult <== 0x1 ==> /sys/block/mmcblk1/device/rel_sectors <== 0x1 ==> /sys/block/mmcblk1/device/serial <== 0x1158f146 ==> /sys/block/mmcblk1/device/subsystem <== ==> /sys/block/mmcblk1/device/type <== MMC ==> /sys/block/mmcblk1/device/uevent <== DRIVER=mmcblk MMC_TYPE=MMC MMC_NAME=MMC02G MODALIAS=mmc:block
root@beaglebone:~/flashbench# cat /sys/kernel/debug/mmc1/* 2>/dev/null | grep -v ^$ 52000000 clock: 52000000 Hz vdd: 7 (1.65 - 1.95 V) bus mode: 2 (push-pull) chip select: 0 (don't care) power mode: 2 (on) bus width: 2 (4 bits) timing spec: 1 (mmc high-speed) signal voltage: 0 (3.30 V) mmc1: ctx_loss: 0:0 regs: CON: 0x00000600 HCTL: 0x00000b06 SYSCTL: 0x000c0087 IE: 0x00000000 ISE: 0x00000000 CAPA: 0x06e10080
root@beaglebone:~/flashbench# dd if=/dev/zero of=/dev/mmcblk1 bs=1M count=256 oflag=direct 256+0 records in 256+0 records out 268435456 bytes (268 MB) copied, 46.5893 s, 5.8 MB/s
root@beaglebone:~/flashbench# dd if=/dev/mmcblk1 of=/dev/null bs=1M count=256 iflag=direct 256+0 records in 256+0 records out 268435456 bytes (268 MB) copied, 15.1334 s, 17.7 MB/s
root@beaglebone:~/flashbench# fdisk -l /dev/mmcblk1 Disk /dev/mmcblk1: 1920 MB, 1920991232 bytes 4 heads, 16 sectors/track, 58624 cylinders, total 3751936 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
root@beaglebone:~/flashbench# ./flashbench -a /dev/mmcblk1 --blocksize=1024 --count=100 align 536870912 pre 1.03ms on 1.48ms post 1.03ms diff 451µs align 268435456 pre 1ms on 1.41ms post 1.01ms diff 403µs align 134217728 pre 978µs on 1.44ms post 918µs diff 488µs align 67108864 pre 932µs on 1.26ms post 782µs diff 407µs align 33554432 pre 981µs on 1.35ms post 923µs diff 393µs align 16777216 pre 988µs on 1.43ms post 992µs diff 442µs align 8388608 pre 993µs on 1.44ms post 989µs diff 446µs align 4194304 pre 904µs on 1.22ms post 740µs diff 398µs align 2097152 pre 992µs on 1.44ms post 984µs diff 448µs align 1048576 pre 989µs on 1.05ms post 991µs diff 57.4µs align 524288 pre 989µs on 1.05ms post 992µs diff 62.4µs align 262144 pre 743µs on 801µs post 746µs diff 56.4µs align 131072 pre 986µs on 1.05ms post 992µs diff 59µs align 65536 pre 983µs on 1.04ms post 987µs diff 54.7µs align 32768 pre 982µs on 1.04ms post 985µs diff 58.6µs align 16384 pre 953µs on 1ms post 937µs diff 55.3µs align 8192 pre 742µs on 794µs post 738µs diff 54µs align 4096 pre 979µs on 1.04ms post 985µs diff 57.5µs align 2048 pre 982µs on 1.02ms post 982µs diff 41.3µs
## Looks like 2 MiB erase blocks
root@beaglebone:~/flashbench# ./flashbench /dev/mmcblk1 --open-au --erasesize=$[2*1024*1024] --blocksize=$[8*1024] --open-au-nr=1 2MiB 2.52M/s 1MiB 2.47M/s 512KiB 2.52M/s 256KiB 2.49M/s 128KiB 2.48M/s 64KiB 2.49M/s 32KiB 2.34M/s 16KiB 2.13M/s 8KiB 1.82M/s
root@beaglebone:~/flashbench# ./flashbench /dev/mmcblk1 --open-au --erasesize=$[2*1024*1024] --blocksize=$[8*1024] --open-au-nr=5 2MiB 4.49M/s 1MiB 3.84M/s 512KiB 4.42M/s 256KiB 4.34M/s 128KiB 4.23M/s 64KiB 4.14M/s 32KiB 3.34M/s 16KiB 1.22M/s 8KiB 927K/s
root@beaglebone:~/flashbench# ./flashbench /dev/mmcblk1 --open-au --erasesize=$[2*1024*1024] --blocksize=$[8*1024] --open-au-nr=6 2MiB 5.66M/s 1MiB 3.33M/s 512KiB 1.27M/s 256KiB 598K/s ^C
## 5 open-au non-random
root@beaglebone:~/flashbench# ./flashbench /dev/mmcblk1 --open-au --erasesize=$[2*1024*1024] --blocksize=$[8*1024] --open-au-nr=5 --random 2MiB 6.16M/s 1MiB 1.6M/s 512KiB 2.48M/s 256KiB 2.51M/s 128KiB 1.64M/s 64KiB 1.27M/s 32KiB 1.07M/s 16KiB 1.21M/s 8KiB 886K/s
root@beaglebone:~/flashbench# ./flashbench /dev/mmcblk1 --open-au --erasesize=$[2*1024*1024] --blocksize=$[8*1024] --open-au-nr=6 --random 2MiB 5.37M/s 1MiB 3.35M/s 512KiB 1.28M/s 256KiB 601K/s 128KiB 295K/s ^C
## 5 open-au in random, too
I expected better but this is a lower end eMMC from Micron.
-Andrew