What do CrystalDiskMark results actually mean? (Samsung 860 EVO - Sata III & Samsung 850 EVO - USB 3.0)

[hazeyez]

I've decided to run the CrystalDiskMark benchmark on my SSD's (and external HDD for the fun of it) - but what do these results actually mean? 

 

What does each category actually mean? 

 

Sequential Read/Write means how fast the drive can read/write 1 large file, correct? But what does "Q32T1" mean?

 

Whats does 4KiB - Q8T8, Q32T1, Q1T1 mean?

 

These following results are on my 500gb Samsung 860 EVO - and are comparatively below par, presumably because it is my boot drive running my OS.

 

-----------------------------------------------------------------------
CrystalDiskMark 6.0.2 x64 (C) 2007-2018 hiyohiyo
                          Crystal Dew World : https://crystalmark.info/
-----------------------------------------------------------------------
* MB/s = 1,000,000 bytes/s [SATA/600 = 600,000,000 bytes/s]
* KB = 1000 bytes, KiB = 1024 bytes

 

   Sequential Read (Q= 32,T= 1) :   471.231 MB/s
  Sequential Write (Q= 32,T= 1) :   324.382 MB/s
  Random Read 4KiB (Q=  8,T= 8 ) :   393.900 MB/s [  96167.0 IOPS]
 Random Write 4KiB (Q=  8,T= 8 ) :   321.975 MB/s [  78607.2 IOPS]
  Random Read 4KiB (Q= 32,T= 1) :   384.970 MB/s [  93986.8 IOPS]
 Random Write 4KiB (Q= 32,T= 1) :   326.315 MB/s [  79666.7 IOPS]
  Random Read 4KiB (Q=  1,T= 1) :    33.779 MB/s [   8246.8 IOPS]
 Random Write 4KiB (Q=  1,T= 1) :   134.580 MB/s [  32856.4 IOPS]

 

  Test : 1024 MiB [C: 26.4% (122.8/465.2 GiB)] (x5)  [Interval=5 sec]
  Date : 2018/12/15 0:48:36
    OS : Windows 10  [10.0 Build 17134] (x64)

 

Also, I found a 250gb Samsung 850 EVO at work, which I formatted and I have hooked up via a USB3.0 Case Adapter. Results are presumably below par as the USB3.0 adapter is bottle necking - was too lazy to unplug and open my case to hook up to SATA - besides, wanted to get actual USB 3.0 results that I could expect - as the setup is being used specifically for my Xbox One to get some better performance out of certain games.

 

Finally - just for the hell of it, I ran the test on my 1TB Western Digital Passport, external HDD - and WOW! I had no idea how slow HDD's were compared to SSD's!!!! (Also presumably slower than a HDD connected thru SATA)

 

 

So - I am curious as to what these different categories actually mean? I've tried to look on youtube and online - only to find basic information.

 

Also - I am running the tests "stock" in the default parameters:

 

Test Count: 5

Test Size: 1GB

Interval Time: 5 seconds

 

Should those be changed at all?

 

 

THANK YOU FOR YOUR HELP!!!!

 

 

 

[Electronics Wizardy]

31 minutes ago, hazeyez said:

So - I am curious as to what these different categories actually mean? I've tried to look on youtube and online - only to find basic information.

Sequentical = access data in a row, so for example sector 1,2,3,4,5,6 in that order.

 

Random = access data randomly, so 2,5,3,6,1,4 for example.

 

Queue depth is how many requests the drive has at one time. Normally on a desktop Its normally 1-4, heavy io uses on servers can queue depth upto around 16, the queue depth 32 test is pretty unrealistic.

 

If a drive has more items in a queue its faster as there is more it can work on at once. Think of it like going to the store to get one item vs getting 10 items at a store. 

 

Threads is how many processes are accessing the drive at once, more processes, higher queue depth, more speed.

 

34 minutes ago, hazeyez said:

Test Count: 5

Test Size: 1GB

Interval Time: 5 seconds

 

Should those be changed at all?

For normal testing this is fine.

 

Some drives has a cache, so a larger test will make the cache less effective and will be slower. The more the counts, the more confident you are in a result(these are averages)

 

Interval allos the drive to rest where it normally will empty the cache between tests.

 

 

 

If you want to go more indepth, crystal disk mark is just a gui for window's disk speed and you can set those value to what ever you want.