Extremely low Random IOPS on two SSDs

[alexo]

Hello,

I have two Samsung SSDs in my computer, an 840 Pro and 860 Evo, both are connected via a SATA3 interface configured as AHCI.
The motherboard is an Asus P8Z77-V Pro, with an i7-3770K CPU.
TRIM is enabled, MB and drive firmware is the latest.

Both drives report sequential performance slightly less than the advertised, but the random IOPS performance is extremely low, about 1/5 of the advertised.


Samsung Magician data:




CrystalDiskMark 8.0.1 results:

840 Pro:
--------

[Read]
  SEQ    1MiB (Q=  8, T= 1):   555.696 MB/s [    530.0 IOPS] < 15045.39 us>
  SEQ    1MiB (Q=  1, T= 1):   513.031 MB/s [    489.3 IOPS] <  2040.42 us>
  RND    4KiB (Q= 32, T= 1):    98.627 MB/s [  24078.9 IOPS] <  1290.06 us>
  RND    4KiB (Q=  1, T= 1):    27.112 MB/s [   6619.1 IOPS] <   149.27 us>

[Write]
  SEQ    1MiB (Q=  8, T= 1):   440.866 MB/s [    420.4 IOPS] < 18900.28 us>
  SEQ    1MiB (Q=  1, T= 1):   486.462 MB/s [    463.9 IOPS] <  2148.58 us>
  RND    4KiB (Q= 32, T= 1):    86.295 MB/s [  21068.1 IOPS] <  1469.22 us>
  RND    4KiB (Q=  1, T= 1):    55.701 MB/s [  13598.9 IOPS] <    71.98 us>


860 Evo:
--------

[Read]
  SEQ    1MiB (Q=  8, T= 1):   564.342 MB/s [    538.2 IOPS] < 14817.95 us>
  SEQ    1MiB (Q=  1, T= 1):   528.124 MB/s [    503.7 IOPS] <  1983.09 us>
  RND    4KiB (Q= 32, T= 1):   105.485 MB/s [  25753.2 IOPS] <  1201.47 us>
  RND    4KiB (Q=  1, T= 1):    33.266 MB/s [   8121.6 IOPS] <   121.58 us>

[Write]
  SEQ    1MiB (Q=  8, T= 1):   534.566 MB/s [    509.8 IOPS] < 15597.54 us>
  SEQ    1MiB (Q=  1, T= 1):   498.652 MB/s [    475.6 IOPS] <  2099.09 us>
  RND    4KiB (Q= 32, T= 1):    92.856 MB/s [  22669.9 IOPS] <  1365.49 us>
  RND    4KiB (Q=  1, T= 1):    61.660 MB/s [  15053.7 IOPS] <    64.86 us>

Suggestions are appreciated.

Thank you!

 

[Johan45]

Those drives are a bit older and CDM 8.0.1 is fairly new so the results may not line up with the advertised numbers. One thing to know about drives and advertised performance is the manufacturer will cherry-pick results from specific test suites to make the product look as good as possible.

 

[alexo]

Samsung's own drive magician reports similar results, which are four to five times lower than what other people are getting.