On Friday 08 February 2013, Csordás Csaba Ifj. wrote:
# fdisk -l /dev/disk/by-id/usb-Generic_USB_SD_Reader_12345678901234567890-0:0
Disk /dev/disk/by-id/usb-Generic_USB_SD_Reader_12345678901234567890-0:0: 31.4 GB, 31393316864 bytes 64 heads, 32 sectors/track, 29939 cylinders, total 61315072 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: 0x000f06a6
I've test a bunch of cards called 'MB-MSBGA' or 'MB-SSBGA' before.
align 536870912 pre 426µs on 921µs post 550µs diff 433µs align 268435456 pre 464µs on 886µs post 500µs diff 404µs align 134217728 pre 466µs on 1.08ms post 541µs diff 576µs align 67108864 pre 487µs on 931µs post 548µs diff 413µs align 33554432 pre 464µs on 961µs post 535µs diff 461µs align 16777216 pre 464µs on 944µs post 529µs diff 448µs align 8388608 pre 458µs on 971µs post 561µs diff 461µs align 4194304 pre 478µs on 954µs post 543µs diff 444µs align 2097152 pre 529µs on 1.3ms post 517µs diff 774µs align 1048576 pre 428µs on 1.1ms post 533µs diff 614µs align 524288 pre 456µs on 892µs post 498µs diff 415µs align 262144 pre 428µs on 891µs post 498µs diff 428µs align 131072 pre 479µs on 967µs post 515µs diff 470µs align 65536 pre 438µs on 945µs post 535µs diff 459µs align 32768 pre 472µs on 954µs post 510µs diff 463µs align 16384 pre 461µs on 684µs post 528µs diff 189µs align 8192 pre 524µs on 526µs post 530µs diff -906ns align 4096 pre 531µs on 531µs post 544µs diff -6887ns align 2048 pre 547µs on 534µs post 561µs diff -20248n
Erase size is 32 MiB, page size unknown.
I don't see the 32 MiB size in the above output, how did you guess that?
oau=30 random 32MiB 11.6M/s 16MiB 11.9M/s 8MiB 11.9M/s 4MiB 11.8M/s 2MiB 11.7M/s 1MiB 11.5M/s 512KiB 10.9M/s 256KiB 9.95M/s 128KiB 8.58M/s 64KiB 6.97M/s 32KiB 4.84M/s 16KiB 3.25M/s 8KiB 1.35M/s 4KiB 720K/s
oau=31 random 32MiB 11.3M/s 16MiB 12M/s 8MiB 12M/s 4MiB 11.9M/s 2MiB 11.7M/s 1MiB 11.6M/s 512KiB 11M/s 256KiB 10.1M/s 128KiB 8.75M/s 64KiB 7.17M/s 32KiB 4.94M/s 16KiB 3.03M/s 8KiB 1.26M/s 4KiB 662K/s
30 open AU. Wow.
Yes, that's the same result I got, although I was never sure exactly about the erase block size. I could verify the result best with a hacked flashbench tool that would only write 256 KB every 32 MB.
My conclusion is definitely that this card is the one I recommend everyone to get. The microSD version is exactly the same, but there are now three other models of each that I have not tested. I know that MSBGA and SSBGA are good like this, while smaller versions (16 GB MSAGA, 8 GB MS8GA) are like your 8GB card, and MP?GA/SP?GA "plus" cards are better than your 8GB but not as good as this one.
The missing new ones are for 32 GB:
* SSBGB/MSBGB (class 6 essential) * SPBGB/MPBGB (class 6 plus) * SPBGC/MPBGC (uhs-1 plus) * SGBGB/MGBGB (uhs-1 pro)
and their smaller cousins. I would hope that at least the "pro" models behave like this one, just with more throughput, while the essential and plus models may just be larger versions of the 16GB SSAGA/MSAGA and SPAGA/MPAGA cards.
# flashbench -f /dev/disk/by-id/usb-Generic_USB_SD_Reader_12345678901234567890-0:0 --count=100 4MiB 11.7M/s 11.9M/s 12M/s 11.5M/s 11.7M/s 11.5M/s 2MiB 12.1M/s 12M/s 12.1M/s 11.5M/s 11.7M/s 11.5M/s 1MiB 12M/s 12.1M/s 12M/s 11.6M/s 11.9M/s 11.9M/s 512KiB 11.7M/s 11.8M/s 11.9M/s 11M/s 11.4M/s 11.5M/s 256KiB 11.3M/s 11.3M/s 11.2M/s 10.4M/s 10.9M/s 11.3M/s 128KiB 10.4M/s 10.5M/s 10.8M/s 9.39M/s 10.1M/s 11M/s 64KiB 11.8M/s 11.8M/s 12.1M/s 11.6M/s 12.1M/s 11.9M/s 32KiB 8.05M/s 8.07M/s 8.2M/s 6.27M/s 7.18M/s 7.99M/s 16KiB 4.83M/s 5.04M/s 4.86M/s 4.76M/s 4.8M/s 4.91M/s
How to interpret this result?
Please help me, including my previous posts.
If there is nothing interesting in the -f output, it usually means the card has no optimization for the FAT area. In this case, that is not surprising, because the card is already very good all over the storage space.
Arnd