Question 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!

 

[UsandThem]

My similar issue was because I was using the Intel AHCI driver, and once I went with the default Microsoft AHCI driver, my drives performed much better. The solution was in post #16.

https://forums.anandtech.com/thread...rus-needed-slow-850-evo-issue-solved.2498047/

 

[alexo]

I am using the Microsoft driver.

 

[Shmee]

From what I can tell, your motherboard should have both Intel and ASmedia 6Gb/s SATA ports. (2 of each.) Are you sure you are connected to the Intel ports? The ASmedia ports will likely not perform as well.

 

[alexo]

Intel ports:

 

[Furious_Styles]

Try different ports and see if you get different results.