On Wednesday 06 February 2013, Csordás Csaba Ifj. wrote:
here are my results. I only have an external card reader.
Thank you very much for sharing the results!
fdisk -l /dev/disk/by-id/usb-Generic-_SD_MMC_20070818000000000-0:2
Disk /dev/disk/by-id/usb-Generic-_SD_MMC_20070818000000000-0:2: 7964 MB, 7964983296 bytes 246 heads, 62 sectors/track, 1019 cylinders, total 15556608 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: 0xa3b9f812
I think I have seen the same device before, with the same name and same size, but I have added your device to the wiki table as well.
# flashbench -a /dev/disk/by-id/usb-Generic-_SD_MMC_20070818000000000-0:2 --blocksize=1024 align 2147483648 pre 1.49ms on 2.26ms post 1.8ms diff 616µs align 1073741824 pre 1.56ms on 2.24ms post 1.71ms diff 607µs align 536870912 pre 1.54ms on 2.19ms post 1.76ms diff 543µs align 268435456 pre 1.37ms on 1.97ms post 1.48ms diff 542µs align 134217728 pre 1.35ms on 1.94ms post 1.55ms diff 493µs align 67108864 pre 1.42ms on 2.1ms post 1.6ms diff 591µs align 33554432 pre 1.34ms on 1.94ms post 1.56ms diff 485µs align 16777216 pre 1.44ms on 2.15ms post 1.64ms diff 608µs align 8388608 pre 1.34ms on 1.9ms post 1.59ms diff 437µs align 4194304 pre 1.42ms on 2.08ms post 1.64ms diff 555µs align 2097152 pre 1.39ms on 2.08ms post 1.59ms diff 599µs align 1048576 pre 1.35ms on 1.73ms post 1.6ms diff 250µs align 524288 pre 1.44ms on 1.82ms post 1.66ms diff 273µs align 262144 pre 1.43ms on 1.79ms post 1.71ms diff 226µs align 131072 pre 1.47ms on 1.83ms post 1.65ms diff 271µs align 65536 pre 1.42ms on 1.77ms post 1.67ms diff 227µs align 32768 pre 1.39ms on 1.73ms post 1.53ms diff 270µs align 16384 pre 1.4ms on 1.82ms post 1.63ms diff 308µs align 8192 pre 1.47ms on 1.78ms post 1.65ms diff 218µs align 4096 pre 1.59ms on 1.58ms post 1.57ms diff 2.05µs align 2048 pre 1.65ms on 1.65ms post 1.61ms diff 18.8µs
My guess is that the erase size is 2 MiB and the pagesize is probably 8 KiB.
I would agree based on this data, but given that the size is a multiple of three, I had done a test with 'flashbench -a --blocksize=3072' to check sizes that are a multiple of three as well, and came to the conclusion that it is actually 6 MB erase blocks.
Only 2 open AU-s. :,(
Yes, sadly.
# flashbench -f --erasesize=$[2 * 1024 * 1024] /dev/disk/by-id/usb-Generic-_SD_MMC_20070818000000000-0:2 --count 100 2MiB 2.84M/s 4.78M/s 8.48M/s 8.45M/s 7.8M/s 7.86M/s 1MiB 8.9M/s 9.07M/s 9.03M/s 9.19M/s 9.17M/s 9.08M/s 512KiB 8.67M/s 8.74M/s 8.49M/s 8.83M/s 8.71M/s 8.52M/s 256KiB 7.19M/s 7.04M/s 6.85M/s 7.19M/s 7.05M/s 6.85M/s 128KiB 5.62M/s 5.84M/s 5.63M/s 5.81M/s 5.87M/s 5.69M/s 64KiB 12.7M/s 13.2M/s 13.3M/s 12.8M/s 13.2M/s 13.3M/s 32KiB 6.09M/s 6.2M/s 6.1M/s 6.27M/s 6.22M/s 6.17M/s 16KiB 3.79M/s 3.73M/s 3.76M/s 3.81M/s 972K/s 3.76M/s
# flashbench -f --erasesize=$[2 * 1024 * 1024] /dev/disk/by-id/usb-Generic-_SD_MMC_20070818000000000-0:2 --count 100 --random 2MiB 9.43M/s 8.57M/s 8.42M/s 8.42M/s 7.8M/s 7.87M/s 1MiB 2.71M/s 3.22M/s 3.2M/s 2.53M/s 3.07M/s 3.23M/s 512KiB 1.06M/s 1.42M/s 1.42M/s 1.28M/s 1.49M/s 1.21M/s 256KiB 465K/s 577K/s 635K/s 756K/s 722K/s 722K/s 128KiB 284K/s 354K/s 343K/s 532K/s 578K/s 577K/s 64KiB 163K/s 172K/s 172K/s 454K/s 431K/s 430K/s 32KiB 151K/s 151K/s 151K/s 211K/s 207K/s 207K/s 16KiB 1.69M/s 3.58M/s 3.72M/s 3.76M/s 3.4M/s 1.41M/s
I don't think it has a FAT optimized area based on this data, although last time I was not sure.
Arnd