Class 10 microSD Cards.

[themirror]

I read this on a sandisk forum that class 10 SD cards have a higher sequential speeds but higher(poor) random access times to 4k/1k data than class 6/4 cards.
I think that's a pretty absurd thing to say. But I'm no expert on this.
Can anyone tell me more about this?

 

[Ravynmagi]

I've heard the same and I think that could very well have been true with Class 10 cards first came out a few years ago. But I don't know if it's still true.

Here is my 32GB Class 4 versus a 64GB Class 10 UHS-1 from 2012 and a Class 10 UHS-1 from 2013.

-----------------------------------------------------------------------
CrystalDiskMark 3.0.3 x64 (C) 2007-2013 hiyohiyo
                           Crystal Dew World : http://crystalmark.info/
-----------------------------------------------------------------------
* MB/s = 1,000,000 byte/s [SATA/300 = 300,000,000 byte/s]

           Sequential Read :    23.479 MB/s
          Sequential Write :     6.234 MB/s
         Random Read 512KB :    22.187 MB/s
        Random Write 512KB :     2.026 MB/s
    Random Read 4KB (QD=1) :     3.446 MB/s [   841.3 IOPS]
   Random Write 4KB (QD=1) :     1.221 MB/s [   298.1 IOPS]
   Random Read 4KB (QD=32) :     3.056 MB/s [   746.2 IOPS]
  Random Write 4KB (QD=32) :     1.169 MB/s [   285.5 IOPS]

  Test : 50 MB [L: 8.5% (10.0/117.4 MB)] (x3)
  Date : 2014/07/19 14:18:22
    OS : Windows 8.1  [6.3 Build 9600] (x64)
    SanDisk 32GB Class 4


-----------------------------------------------------------------------
CrystalDiskMark 3.0.3 x64 (C) 2007-2013 hiyohiyo
                           Crystal Dew World : http://crystalmark.info/
-----------------------------------------------------------------------
* MB/s = 1,000,000 byte/s [SATA/300 = 300,000,000 byte/s]

           Sequential Read :    45.710 MB/s
          Sequential Write :    19.318 MB/s
         Random Read 512KB :    40.874 MB/s
        Random Write 512KB :     3.669 MB/s
    Random Read 4KB (QD=1) :     4.200 MB/s [  1025.5 IOPS]
   Random Write 4KB (QD=1) :     1.180 MB/s [   288.2 IOPS]
   Random Read 4KB (QD=32) :     4.270 MB/s [  1042.4 IOPS]
  Random Write 4KB (QD=32) :     1.823 MB/s [   445.1 IOPS]

  Test : 50 MB [L: 27.7% (16.5/59.4 GB)] (x3)
  Date : 2014/07/19 14:06:13
    OS : Windows 8.1  [6.3 Build 9600] (x64)
    Sandisk Ultra 64GB Class 10 UHS-1


-----------------------------------------------------------------------
CrystalDiskMark 3.0.3 x64 (C) 2007-2013 hiyohiyo
                           Crystal Dew World : http://crystalmark.info/
-----------------------------------------------------------------------
* MB/s = 1,000,000 byte/s [SATA/300 = 300,000,000 byte/s]

           Sequential Read :    93.199 MB/s
          Sequential Write :    60.641 MB/s
         Random Read 512KB :    79.438 MB/s
        Random Write 512KB :    36.481 MB/s
    Random Read 4KB (QD=1) :     6.152 MB/s [  1502.0 IOPS]
   Random Write 4KB (QD=1) :     2.051 MB/s [   500.7 IOPS]
   Random Read 4KB (QD=32) :     6.169 MB/s [  1506.0 IOPS]
  Random Write 4KB (QD=32) :     2.059 MB/s [   502.7 IOPS]

  Test : 50 MB [L: 47.2% (28.0/59.4 GB)] (x3)
  Date : 2014/07/19 14:13:01
    OS : Windows 8.1  [6.3 Build 9600] (x64)
    SanDisk Extreme Plus Class 10 UHS-1

 

[themirror]

But the two UHS 1 cards are different. Isn't the extreme plus a higher end model? It costs twice the ultra.