1. dcreed's Avatar
    I keep seeing people misunderstanding what the class rankings of microSD cards are and mean. And, unfortunately, there's no independent rating authority to guarantee that some company claiming to have a Class 6 card really is a Class 6 card. So if people want to chime in with their real-world measurements of cards, that'd be great.

    First of all, Mb means Megabits or millions of bits, MB means Megabytes or millions of bytes -- 8 bits in a byte. Computer Science 101, folks. So pay attention when your cable provider uses an upper-case or lower-case "b" in their advertising.

    Class 2: read/write at 16Mbits/second (~1.9 MB/second).
    Class 4: read/write 32 Mbits/second (~3.9 MB/sec).
    Class 6: read/write 48Mbits/second (~5.7 MB/sec).
    Class 10: read/write 160 Mbits/second (~19 MB/sec).

    win32diskImager, which you'll probably be using to write an image to a microSD card, will give you a basic rating of how fast it's writing to your card...or reading from it when you make a backup -- and I recommend backup images so you don't have to start completely over sometime. I'm sure others will recommend other things like Sandra for measuring speed, and they're probably more accurate.

    Your card-reader is probably hooked up to a USB 2.0 bus on your motherboard, and that's 480 Mbits/second, so don't try to blame that as the bottleneck; unless you're running USB 1.0 which is only 12 Mbits/second.

    Just thought you'd like to know.
    smartmosey and Alma like this.
    02-13-2011 06:46 PM
  2. Mark_Venture's Avatar
    ...And, unfortunately, there's no independent rating authority to guarantee that some company claiming to have a Class 6 card really is a Class 6 card. So if people want to chime in with their real-world measurements of cards, that'd be great.
    Real world experiences would be appreciated! Especially if they include brand, model number of the card, and where purchased from.
    02-14-2011 08:50 AM
  3. dcreed's Avatar
    I just used CrystalDiskMark 3.01 to do my bencharking. Did 50MB read/writes, 5 iterations.

    An ADATA 8GB "Class 6" microSD card (from MicroCenter):
    Sequential Read: 18.25 MB/s (~Class 10)
    Sequential Write: 5.46 MB/s (~Class 6)
    512KB Random Read: 18.29 MB/s (~Class 10)
    512KB Random Write: 0.98 MB/s (~Class Kaka)
    4KB Random Read: 4.06 MB/s (~Class 4)
    4KB Random Write: 0.01 MB/s (~Class Sewage)

    By comparison, an Extreme III ("Class 6") SanDisk SD card I use for my 15Mp camera:
    Sequential Read: 19.99 MB/s (~Class 10)
    Sequential Write: 19.01 MB/s (~Class 10)
    512KB Random Read: 19.71 MB/s (~Class 10)
    512KB Random Write: 3.65 MB/s (~Class 4)
    4KB Random Read: 3.52 MB/s (~Class 4)
    4KB Random Write: 0.04 MB/s (~Class Bupkiss)
    02-14-2011 10:02 AM
  4. Mark_Venture's Avatar
    Sandisk 16gig Class2 (that came installed in one of my phones) Did 50MB, 5 iterations


    run using the 32bit version CrystalDiskMark...
    -----------------------------------------------------------------------
    CrystalDiskMark 3.0.1 (C) 2007-2010 hiyohiyo
    Crystal Dew World : Crystal Dew World
    -----------------------------------------------------------------------
    * MB/s = 1,000,000 byte/s [SATA/300 = 300,000,000 byte/s]

    Sequential Read : 21.818 MB/s
    Sequential Write : 6.910 MB/s
    Random Read 512KB : 21.443 MB/s
    Random Write 512KB : 0.969 MB/s
    Random Read 4KB (QD=1) : 4.490 MB/s [ 1096.2 IOPS]
    Random Write 4KB (QD=1) : 0.011 MB/s [ 2.6 IOPS]
    Random Read 4KB (QD=32) : 4.507 MB/s [ 1100.4 IOPS]
    Random Write 4KB (QD=32) : 0.016 MB/s [ 3.8 IOPS]

    Test : 50 MB [P: 0.6% (0.1/14.8 GB)] (x5)
    Date : 2011/02/14 13:40:30
    OS : Windows 7 Ultimate Edition [6.1 Build 7600] (x64)




    here using the same test running as 64bit CrystalDiskMark

    -----------------------------------------------------------------------
    CrystalDiskMark 3.0.1 x64 (C) 2007-2010 hiyohiyo
    Crystal Dew World : http://crystalmark.info/
    -----------------------------------------------------------------------
    * MB/s = 1,000,000 byte/s [SATA/300 = 300,000,000 byte/s]

    Sequential Read : 21.809 MB/s
    Sequential Write : 7.429 MB/s
    Random Read 512KB : 21.453 MB/s
    Random Write 512KB : 1.268 MB/s
    Random Read 4KB (QD=1) : 4.385 MB/s [ 1070.7 IOPS]
    Random Write 4KB (QD=1) : 0.011 MB/s [ 2.6 IOPS]
    Random Read 4KB (QD=32) : 4.542 MB/s [ 1108.8 IOPS]
    Random Write 4KB (QD=32) : 0.017 MB/s [ 4.0 IOPS]

    Test : 50 MB [P: 0.6% (0.1/14.8 GB)] (x5)
    Date : 2011/02/14 13:21:03
    OS : Windows 7 Ultimate Edition [6.1 Build 7600] (x64)
    philn likes this.
    02-14-2011 12:41 PM
  5. dcreed's Avatar
    So your Sandisk Class 2 outgunned the Adata Class 6. Nice. It was the only card I could find around here for a decent price, but I guess I got what I paid for. Now off to NewEgg....
    02-14-2011 01:03 PM
  6. Mark_Venture's Avatar
    One thing to note.. my cards were BLANK and formatted as Fat32 if that makes any difference.
    02-14-2011 01:37 PM
  7. Mark_Venture's Avatar
    "no-name" 16gig MicroSDHC class 4 that came with my Droid X...

    -----------------------------------------------------------------------
    CrystalDiskMark 3.0.1 x64 (C) 2007-2010 hiyohiyo
    Crystal Dew World : Crystal Dew World
    -----------------------------------------------------------------------
    * MB/s = 1,000,000 byte/s [SATA/300 = 300,000,000 byte/s]

    Sequential Read : 13.837 MB/s
    Sequential Write : 8.542 MB/s
    Random Read 512KB : 13.558 MB/s
    Random Write 512KB : 1.182 MB/s
    Random Read 4KB (QD=1) : 2.804 MB/s [ 684.5 IOPS]
    Random Write 4KB (QD=1) : 0.011 MB/s [ 2.6 IOPS]
    Random Read 4KB (QD=32) : 3.237 MB/s [ 790.4 IOPS]
    Random Write 4KB (QD=32) : 0.023 MB/s [ 5.5 IOPS]

    Test : 50 MB [P: 0.0% (0.0/14.9 GB)] (x5)
    Date : 2011/02/14 15:16:54
    OS : Windows 7 Ultimate Edition [6.1 Build 7600] (x64)
    02-14-2011 02:18 PM
  8. EricWiz's Avatar
    Here is another benchmark. The card is a SanDisk class 2 4GB
    -----------------------------------------------------------------------
    CrystalDiskMark 3.0.1 x64 (C) 2007-2010 hiyohiyo
    Crystal Dew World : Crystal Dew World
    -----------------------------------------------------------------------
    * MB/s = 1,000,000 byte/s [SATA/300 = 300,000,000 byte/s]

    Sequential Read : 10.760 MB/s
    Sequential Write : 5.305 MB/s
    Random Read 512KB : 10.656 MB/s
    Random Write 512KB : 2.064 MB/s
    Random Read 4KB (QD=1) : 3.943 MB/s [ 962.8 IOPS]
    Random Write 4KB (QD=1) : 0.030 MB/s [ 7.3 IOPS]
    Random Read 4KB (QD=32) : 3.968 MB/s [ 968.7 IOPS]
    Random Write 4KB (QD=32) : 0.031 MB/s [ 7.6 IOPS]

    Test : 50 MB [K: 0.0% (0.0/3867.5 MB)] (x5)
    Date : 2011/02/23 12:33:05
    OS : Windows 7 Ultimate Edition [6.1 Build 7600] (x64)

    Here is PNY 8GB Class 4
    -----------------------------------------------------------------------
    CrystalDiskMark 3.0.1 x64 (C) 2007-2010 hiyohiyo
    Crystal Dew World : Crystal Dew World
    -----------------------------------------------------------------------
    * MB/s = 1,000,000 byte/s [SATA/300 = 300,000,000 byte/s]

    Sequential Read : 14.802 MB/s
    Sequential Write : 9.053 MB/s
    Random Read 512KB : 14.123 MB/s
    Random Write 512KB : 1.295 MB/s
    Random Read 4KB (QD=1) : 2.924 MB/s [ 713.8 IOPS]
    Random Write 4KB (QD=1) : 0.011 MB/s [ 2.7 IOPS]
    Random Read 4KB (QD=32) : 3.436 MB/s [ 838.9 IOPS]
    Random Write 4KB (QD=32) : 0.011 MB/s [ 2.7 IOPS]

    Test : 50 MB [K: 5.2% (6.0/115.8 MB)] (x5)
    Date : 2011/02/23 12:56:54
    OS : Windows 7 Ultimate Edition [6.1 Build 7600] (x64)
    02-23-2011 11:34 AM
  9. EricWiz's Avatar
    Another card to add to the list. this time its a Patriot 8GB class 10
    Same benchmark settings for apples to apples comparison.

    -----------------------------------------------------------------------
    CrystalDiskMark 3.0.1 x64 (C) 2007-2010 hiyohiyo
    Crystal Dew World : Crystal Dew World
    -----------------------------------------------------------------------
    * MB/s = 1,000,000 byte/s [SATA/300 = 300,000,000 byte/s]

    Sequential Read : 17.708 MB/s
    Sequential Write : 10.700 MB/s
    Random Read 512KB : 17.897 MB/s
    Random Write 512KB : 1.142 MB/s
    Random Read 4KB (QD=1) : 4.113 MB/s [ 1004.1 IOPS]
    Random Write 4KB (QD=1) : 0.013 MB/s [ 3.1 IOPS]
    Random Read 4KB (QD=32) : 4.503 MB/s [ 1099.3 IOPS]
    Random Write 4KB (QD=32) : 0.022 MB/s [ 5.4 IOPS]

    Test : 50 MB [K: 0.0% (0.0/7631.0 MB)] (x5)
    Date : 2011/03/01 19:33:04
    OS : Windows 7 Ultimate Edition [6.1 Build 7600] (x64)
    03-01-2011 06:41 PM
  10. swoozle's Avatar
    Kingston Class 4 4 Gig

    -----------------------------------------------------------------------
    CrystalDiskMark 3.0.1 (C) 2007-2010 hiyohiyo
    Crystal Dew World : Crystal Dew World
    -----------------------------------------------------------------------
    * MB/s = 1,000,000 byte/s [SATA/300 = 300,000,000 byte/s]

    Sequential Read : 18.700 MB/s
    Sequential Write : 4.277 MB/s
    Random Read 512KB : 17.269 MB/s
    Random Write 512KB : 0.677 MB/s
    Random Read 4KB (QD=1) : 2.011 MB/s [ 490.9 IOPS]
    Random Write 4KB (QD=1) : 0.006 MB/s [ 1.5 IOPS]
    Random Read 4KB (QD=32) : 2.088 MB/s [ 509.7 IOPS]
    Random Write 4KB (QD=32) : 0.016 MB/s [ 3.9 IOPS]

    Test : 50 MB [N: 0.0% (0.0/3750.0 MB)] (x5)
    Date : 2011/03/01 19:39:27
    OS : Windows XP Home Edition SP3 [5.1 Build 2600] (x86)
    03-01-2011 09:41 PM
  11. swoozle's Avatar
    Patriot 8 gig Class 10

    -----------------------------------------------------------------------
    CrystalDiskMark 3.0.1 (C) 2007-2010 hiyohiyo
    Crystal Dew World : Crystal Dew World
    -----------------------------------------------------------------------
    * MB/s = 1,000,000 byte/s [SATA/300 = 300,000,000 byte/s]

    Sequential Read : 20.049 MB/s
    Sequential Write : 13.894 MB/s
    Random Read 512KB : 19.281 MB/s
    Random Write 512KB : 1.687 MB/s
    Random Read 4KB (QD=1) : 2.418 MB/s [ 590.2 IOPS]
    Random Write 4KB (QD=1) : 0.014 MB/s [ 3.5 IOPS]
    Random Read 4KB (QD=32) : 3.324 MB/s [ 811.6 IOPS]
    Random Write 4KB (QD=32) : 0.034 MB/s [ 8.4 IOPS]

    Test : 50 MB [N: 5.0% (5.8/115.8 MB)] (x5)
    Date : 2011/03/01 20:25:41
    OS : Windows XP Home Edition SP3 [5.1 Build 2600] (x86)
    03-01-2011 10:27 PM
  12. crspy's Avatar
    I believe the 4k is what affects performance the most. It's similar to access time correct? (it's slower but it's the "real" world access time) Also everyone should benchmark the cards specifically on the nook color, so we know the physical limitations of the device and buy a card accordingly. Just some thoughts
    03-02-2011 06:09 AM
  13. surfmly29's Avatar
    Here is a Transcend 16GB Class 6. Heard some good things about this card (and just could not find a SanDisk this size and class):

    -----------------------------------------------------------------------
    CrystalDiskMark 3.0.1 x64 (C) 2007-2010 hiyohiyo
    Crystal Dew World : Crystal Dew World
    -----------------------------------------------------------------------
    * MB/s = 1,000,000 byte/s [SATA/300 = 300,000,000 byte/s]

    Sequential Read : 20.031 MB/s
    Sequential Write : 20.445 MB/s
    Random Read 512KB : 19.590 MB/s
    Random Write 512KB : 2.227 MB/s
    Random Read 4KB (QD=1) : 3.165 MB/s [ 772.8 IOPS]
    Random Write 4KB (QD=1) : 0.030 MB/s [ 7.3 IOPS]
    Random Read 4KB (QD=32) : 3.468 MB/s [ 846.6 IOPS]
    Random Write 4KB (QD=32) : 0.033 MB/s [ 8.1 IOPS]

    Test : 50 MB [H: 0.0% (0.0/14.9 GB)] (x3)
    Date : 2011/03/08 19:15:55
    OS : Windows 7 Home Premium Edition SP1 [6.1 Build 7601] (x64)

    I'll try and post again with times from running it on my NOOK, once I get things running on it.

    NOTE: I tried a cheaper Patriot 16GB Class 4 first (from local Frys) and it had such low marks I didn't even take the time to copy the test details, I just returned it on the spot.
    03-08-2011 09:26 PM
  14. dcreed's Avatar
    Re-posting the definitions so folks don't have to refer back to page 1 of this thread all the time.

    Class 2: read/write at 16Mbits/second (~1.9 MB/second).
    Class 4: read/write 32 Mbits/second (~3.9 MB/sec).
    Class 6: read/write 48Mbits/second (~5.7 MB/sec).
    Class 10: read/write 160 Mbits/second (~19 MB/sec).
    03-09-2011 08:30 AM
  15. met67's Avatar
    SanDisk 8GB Class 4
    -----------------------------------------------------------------------
    CrystalDiskMark 3.0.1 x64 (C) 2007-2010 hiyohiyo
    Crystal Dew World : Crystal Dew World
    -----------------------------------------------------------------------
    * MB/s = 1,000,000 byte/s [SATA/300 = 300,000,000 byte/s]

    Sequential Read : 17.787 MB/s
    Sequential Write : 12.573 MB/s
    Random Read 512KB : 16.139 MB/s
    Random Write 512KB : 3.485 MB/s
    Random Read 4KB (QD=1) : 2.830 MB/s [ 690.9 IOPS]
    Random Write 4KB (QD=1) : 0.041 MB/s [ 10.0 IOPS]
    Random Read 4KB (QD=32) : 2.998 MB/s [ 731.9 IOPS]
    Random Write 4KB (QD=32) : 0.048 MB/s [ 11.7 IOPS]

    Test : 50 MB [E: 9.9% (772.1/7774.1 MB)] (x5)
    Date : 2011/03/09 22:42:29
    OS : Windows 7 Enterprise Edition [6.1 Build 7600] (x64)


    Kingston 16GB Class 4
    -----------------------------------------------------------------------
    CrystalDiskMark 3.0.1 (C) 2007-2010 hiyohiyo
    Crystal Dew World : Crystal Dew World
    -----------------------------------------------------------------------
    * MB/s = 1,000,000 byte/s [SATA/300 = 300,000,000 byte/s]

    Sequential Read : 13.376 MB/s
    Sequential Write : 7.404 MB/s
    Random Read 512KB : 13.130 MB/s
    Random Write 512KB : 1.604 MB/s
    Random Read 4KB (QD=1) : 2.081 MB/s [ 508.0 IOPS]
    Random Write 4KB (QD=1) : 0.031 MB/s [ 7.6 IOPS]
    Random Read 4KB (QD=32) : 2.389 MB/s [ 583.3 IOPS]
    Random Write 4KB (QD=32) : 0.040 MB/s [ 9.8 IOPS]

    Test : 50 MB [E: 53.8% (7.8/14.4 GB)] (x5)
    Date : 2011/03/09 22:54:04
    OS : Windows 7 Enterprise Edition [6.1 Build 7600] (x64)


    SanDisk 4GB Class 2(?)
    -----------------------------------------------------------------------
    CrystalDiskMark 3.0.1 (C) 2007-2010 hiyohiyo
    Crystal Dew World : Crystal Dew World
    -----------------------------------------------------------------------
    * MB/s = 1,000,000 byte/s [SATA/300 = 300,000,000 byte/s]

    Sequential Read : 11.772 MB/s
    Sequential Write : 4.500 MB/s
    Random Read 512KB : 11.398 MB/s
    Random Write 512KB : 0.544 MB/s
    Random Read 4KB (QD=1) : 1.724 MB/s [ 420.9 IOPS]
    Random Write 4KB (QD=1) : 0.022 MB/s [ 5.4 IOPS]
    Random Read 4KB (QD=32) : 2.034 MB/s [ 496.6 IOPS]
    Random Write 4KB (QD=32) : 0.025 MB/s [ 6.0 IOPS]

    Test : 50 MB [E: 29.9% (1121.2/3751.0 MB)] (x5)
    Date : 2011/03/09 23:08:01
    OS : Windows 7 Enterprise Edition [6.1 Build 7600] (x64)


    SanDisk 1GB no class
    -----------------------------------------------------------------------
    CrystalDiskMark 3.0.1 (C) 2007-2010 hiyohiyo
    Crystal Dew World : Crystal Dew World
    -----------------------------------------------------------------------
    * MB/s = 1,000,000 byte/s [SATA/300 = 300,000,000 byte/s]

    Sequential Read : 17.009 MB/s
    Sequential Write : 4.267 MB/s
    Random Read 512KB : 14.251 MB/s
    Random Write 512KB : 2.013 MB/s
    Random Read 4KB (QD=1) : 2.262 MB/s [ 552.3 IOPS]
    Random Write 4KB (QD=1) : 0.019 MB/s [ 4.7 IOPS]
    Random Read 4KB (QD=32) : 2.801 MB/s [ 683.8 IOPS]
    Random Write 4KB (QD=32) : 0.023 MB/s [ 5.5 IOPS]

    Test : 50 MB [E: 18.6% (68.0/364.6 MB)] (x5)
    Date : 2011/03/09 23:31:02
    OS : Windows 7 Enterprise Edition [6.1 Build 7600] (x64)
    03-09-2011 04:43 PM
  16. joejoe's Avatar
    Transcend 8GB Class 6

    -----------------------------------------------------------------------
    CrystalDiskMark 3.0.1 (C) 2007-2010 hiyohiyo
    Crystal Dew World : Crystal Dew World
    -----------------------------------------------------------------------
    * MB/s = 1,000,000 byte/s [SATA/300 = 300,000,000 byte/s]

    Sequential Read : 19.121 MB/s
    Sequential Write : 17.722 MB/s
    Random Read 512KB : 18.034 MB/s
    Random Write 512KB : 1.610 MB/s
    Random Read 4KB (QD=1) : 2.843 MB/s [ 694.1 IOPS]
    Random Write 4KB (QD=1) : 0.015 MB/s [ 3.7 IOPS]
    Random Read 4KB (QD=32) : 3.168 MB/s [ 773.5 IOPS]
    Random Write 4KB (QD=32) : 0.031 MB/s [ 7.6 IOPS]

    Test : 50 MB [E: 1.8% (140.0/7639.0 MB)] (x5)
    Date : 2011/03/24 5:37:49
    OS : Windows XP Professional SP3 [5.1 Build 2600] (x86)

    Sandisk 2GB No Class

    -----------------------------------------------------------------------
    CrystalDiskMark 3.0.1 (C) 2007-2010 hiyohiyo
    Crystal Dew World : Crystal Dew World
    -----------------------------------------------------------------------
    * MB/s = 1,000,000 byte/s [SATA/300 = 300,000,000 byte/s]

    Sequential Read : 8.009 MB/s
    Sequential Write : 6.074 MB/s
    Random Read 512KB : 7.964 MB/s
    Random Write 512KB : 1.141 MB/s
    Random Read 4KB (QD=1) : 3.815 MB/s [ 931.5 IOPS]
    Random Write 4KB (QD=1) : 0.014 MB/s [ 3.3 IOPS]
    Random Read 4KB (QD=32) : 4.028 MB/s [ 983.4 IOPS]
    Random Write 4KB (QD=32) : 0.013 MB/s [ 3.2 IOPS]

    Test : 50 MB [F: 80.3% (1441.8/1796.5 MB)] (x5)
    Date : 2011/03/24 5:56:30
    OS : Windows XP Professional SP3 [5.1 Build 2600] (x86)


    Kingston 8GB Class 4


    -----------------------------------------------------------------------
    CrystalDiskMark 3.0.1 (C) 2007-2010 hiyohiyo
    Crystal Dew World : Crystal Dew World
    -----------------------------------------------------------------------
    * MB/s = 1,000,000 byte/s [SATA/300 = 300,000,000 byte/s]

    Sequential Read : 14.899 MB/s
    Sequential Write : 4.180 MB/s
    Random Read 512KB : 14.517 MB/s
    Random Write 512KB : 0.693 MB/s
    Random Read 4KB (QD=1) : 1.919 MB/s [ 468.5 IOPS]
    Random Write 4KB (QD=1) : 0.006 MB/s [ 1.5 IOPS]
    Random Read 4KB (QD=32) : 2.047 MB/s [ 499.7 IOPS]
    Random Write 4KB (QD=32) : 0.006 MB/s [ 1.5 IOPS]

    Test : 50 MB [E: 1.9% (143.8/7590.0 MB)] (x5)
    Date : 2011/03/24 6:20:17
    OS : Windows XP Professional SP3 [5.1 Build 2600] (x86)
    03-23-2011 05:20 PM
  17. Mark_Venture's Avatar
    Generic "Taiwan" 8Gig Class 4 from my Moto Devour...

    -----------------------------------------------------------------------
    CrystalDiskMark 3.0.1 x64 (C) 2007-2010 hiyohiyo
    Crystal Dew World : Crystal Dew World
    -----------------------------------------------------------------------
    * MB/s = 1,000,000 byte/s [SATA/300 = 300,000,000 byte/s]

    Sequential Read : 14.804 MB/s
    Sequential Write : 8.046 MB/s
    Random Read 512KB : 14.441 MB/s
    Random Write 512KB : 1.141 MB/s
    Random Read 4KB (QD=1) : 3.000 MB/s [ 732.5 IOPS]
    Random Write 4KB (QD=1) : 0.011 MB/s [ 2.6 IOPS]
    Random Read 4KB (QD=32) : 3.556 MB/s [ 868.1 IOPS]
    Random Write 4KB (QD=32) : 0.023 MB/s [ 5.6 IOPS]

    Test : 50 MB [P: 0.0% (0.0/7586.2 MB)] (x5)
    Date : 2011/03/31 15:54:53
    OS : Windows 7 Ultimate Edition SP1 [6.1 Build 7601] (x64)
    03-31-2011 02:56 PM
  18. Mark_Venture's Avatar
    Sandisk 8gig Class 4 SDSDQ-008G-A11M (purchased at staples)


    -----------------------------------------------------------------------
    CrystalDiskMark 3.0.1 x64 (C) 2007-2010 hiyohiyo
    Crystal Dew World : Crystal Dew World
    -----------------------------------------------------------------------
    * MB/s = 1,000,000 byte/s [SATA/300 = 300,000,000 byte/s]

    Sequential Read : 9.092 MB/s
    Sequential Write : 5.241 MB/s
    Random Read 512KB : 8.759 MB/s
    Random Write 512KB : 3.960 MB/s
    Random Read 4KB (QD=1) : 1.155 MB/s [ 282.1 IOPS]
    Random Write 4KB (QD=1) : 0.606 MB/s [ 148.0 IOPS]
    Random Read 4KB (QD=32) : 1.058 MB/s [ 258.4 IOPS]
    Random Write 4KB (QD=32) : 0.608 MB/s [ 148.4 IOPS]

    Test : 50 MB [P: 0.0% (0.0/7572.0 MB)] (x5)
    Date : 2011/03/31 16:03:32
    OS : Windows 7 Ultimate Edition SP1 [6.1 Build 7601] (x64)
    03-31-2011 03:03 PM
  19. Mark_Venture's Avatar
    Sandisk 8gig Class 4 SDSDQ-8192-AB11M (purchased from BestBuy)


    -----------------------------------------------------------------------
    CrystalDiskMark 3.0.1 x64 (C) 2007-2010 hiyohiyo
    Crystal Dew World : Crystal Dew World
    -----------------------------------------------------------------------
    * MB/s = 1,000,000 byte/s [SATA/300 = 300,000,000 byte/s]

    Sequential Read : 10.918 MB/s
    Sequential Write : 6.142 MB/s
    Random Read 512KB : 10.786 MB/s
    Random Write 512KB : 1.613 MB/s
    Random Read 4KB (QD=1) : 3.351 MB/s [ 818.1 IOPS]
    Random Write 4KB (QD=1) : 1.590 MB/s [ 388.1 IOPS]
    Random Read 4KB (QD=32) : 3.079 MB/s [ 751.7 IOPS]
    Random Write 4KB (QD=32) : 1.226 MB/s [ 299.2 IOPS]

    Test : 50 MB [P: 5.5% (6.4/115.8 MB)] (x5)
    Date : 2011/03/31 16:30:40
    OS : Windows 7 Ultimate Edition SP1 [6.1 Build 7601] (x64)
    03-31-2011 03:30 PM
  20. stricknook's Avatar
    does anyone have any info bout using the portable tarabite drives? the ones used to supp wii's,or is the micro card it.(been putting along ww/3 4gb micros but havent had the scratch to get a hi gig card)or any actual info on interesting developments on acc.(blue tooth stuff, handsfree headsets wifi keyboard/dock stations,exter drives, hardware stuff with nothing to do with phones.
    or directions to not a f!%$Y@^Y blog site.
    03-31-2011 06:32 PM
  21. stricknook's Avatar
    the NC getting opened up has made android/google golden(fine,opinion) is a shortcut button and or a tab too much? just because theres info to be found here dosent mean we are not made to dig past the phone stuff first.
    and is this more of a stich and bitc#$ site or more or less tech. than xda?
    03-31-2011 06:52 PM
  22. jmunchies1's Avatar
    Here's a 32GB San Disk card I picked up off Amazon, the bulk one. No class label.


    -----------------------------------------------------------------------
    CrystalDiskMark 3.0.1 x64 (C) 2007-2010 hiyohiyo
    Crystal Dew World : Crystal Dew World
    -----------------------------------------------------------------------
    * MB/s = 1,000,000 byte/s [SATA/300 = 300,000,000 byte/s]

    Sequential Read : 10.555 MB/s
    Sequential Write : 6.210 MB/s
    Random Read 512KB : 10.409 MB/s
    Random Write 512KB : 6.692 MB/s
    Random Read 4KB (QD=1) : 1.032 MB/s [ 252.0 IOPS]
    Random Write 4KB (QD=1) : 2.545 MB/s [ 621.4 IOPS]
    Random Read 4KB (QD=32) : 0.719 MB/s [ 175.5 IOPS]
    Random Write 4KB (QD=32) : 2.674 MB/s [ 652.8 IOPS]

    Test : 50 MB [D: 0.0% (0.0/29.7 GB)] (x5)
    Date : 2011/04/09 15:49:07
    OS : Windows 7 SP1 [6.1 Build 7601] (x64)



    I actually don't have my Nook yet, it's coming soon, but I'm pretty disappointed with those numbers. I plan on install a rom to the internal memory, but even for copying files to the card for storage seems like it's going to be really slow.

    Anybody have any 32GB card recommendations?
    04-09-2011 03:50 PM
  23. denshigomi's Avatar
    I keep seeing people misunderstanding what the class rankings of microSD cards are and mean.
    ...
    Class 2: read/write at 16Mbits/second (~1.9 MB/second).
    Class 4: read/write 32 Mbits/second (~3.9 MB/sec).
    Class 6: read/write 48Mbits/second (~5.7 MB/sec).
    Class 10: read/write 160 Mbits/second (~19 MB/sec).
    This is wrong.

    The class number represents the minimum guaranteed sustained data transfer rate of the card in megabytes per second. Very simple.

    Class 2 = 2 megabytes per second.
    Class 4 = 4 megabytes per second.
    Class 6 = 6 megabytes per second.
    Class 10 = 10 megabytes per second.

    No knowledge of bits versus bytes is needed.

    Your megabytes per second values are all incorrect.
    And for class 10, both your bit and byte values are wildly incorrect.
    04-11-2011 04:06 AM
LINK TO POST COPIED TO CLIPBOARD