Samsung 850 EVO M.2. and mSATA SSD review

I/O Performance

There is little point of having an SSD drive that has
blazing sustained reading and writing speeds, if the drive can’t handle reading
and writing of small random files. If you intend to use your new SSD drive to
store and run your operating system, then the drive must be able to cope with
the many small random files that Windows will write to the drive continually.
So I feel it is very important to test how many of these random files that a
drive can handle in one second. I believe that anything over 1,000 I/O’s per
second would be enough for most users running a consumer grade mainstream PC,
and should provide a smooth running system. But obviously, the more I/O’s that
a drive can handle, the faster the drive will feel and leave more headroom for
those huge multitasking sessions that users sometimes engage in.

IOMeter is probably the most versatile of all the synthetic
benchmarks. Its ability to be configured to generate a multitude of different
I/O traffic is unmatched. Another great feature of IOMeter, is the capability
to test any storage metric that you can think of, providing you know how to
configure the assignments. The reviewer also has complete control over things
like queue depth, block size, whether the traffic is random, sequential, or
even a mixture of both.

Partition alignment and sector boundaries

Windows 8.1, Windows 7, and Windows Vista will automatically
align a partition to 4k boundaries during partition creation, Windows XP won’t.
It is imperative that an SSD’s partition is aligned. Windows XP is also
restricted to sector boundaries, while Windows 7 and 8 will use 4k boundaries
if they can. The Samsung 850 EVO SSD is 4k boundary aware, and will use these
boundaries if possible. Of course it will also remap LBAs for compatibility
with the sector boundaries so that the drive can be used with Windows XP.

ADVERTISEMENT

IOMeter allows us to set the sector boundaries for
conducting the tests, and I have therefore set the sector boundaries at 4K,
which means the IOMeter tests are valid for Windows 7, Windows 8, and Windows
Vista users. XP users will not be able to obtain such results.

I will provide a screenshot of the tests on the review drive
for those of you who like to see the actual test result. All the comparison
drive results are represented in the form of graphs.

If any of you would like to see a screenshot from any
IOMeter test on a particular drive, please feel free to request one, and I’ll
post the screenshot in the forum thread.

All the IOMeter tests create a 10GB data set on the target
drive, and each test is run for a duration of 3 minutes.


IOMeter 4K random write test with repeating data.

The first test involves creating continual 4KB random files
on the target drive with IOMeter. I use a 4KB file size, as it is believed that
Windows will create and modify many of this size of file constantly in the
background during a typical Windows session. It is said that most 4K random
writes take place at a queue depth of only one, and I have been requested to
include this test in my reviews.

ADVERTISEMENT

Queue depth 1

Samsung 850 EVO M.2. and mSATA SSD review

Samsung 850 EVO mSATA
500GB SSD – 4K random write (QD 1)

Samsung 850 EVO M.2. and mSATA SSD review

Samsung 850 EVO M.2
250GB SSD – 4K random write (QD 1)

Samsung 850 EVO M.2. and mSATA SSD review

ADVERTISEMENT

At 154 MB/s the Samsung 850 EVO SSDs are excellent, and finish
this test in fourth and fifth places respectively.

Our next test involves creating continual 4KB random files
on the target drive with IOMeter. I use a 4KB file size, as it is believed that
Windows will create and modify many of this size of file constantly in the
background during a typical Windows session. I will use queue depths of 4 and
32 for these tests.

Queue depth 4

Samsung 850 EVO M.2. and mSATA SSD review

Samsung
850 EVO mSATA 500GB SSD (QD 4)

ADVERTISEMENT

Samsung 850 EVO M.2. and mSATA SSD review

Samsung
850 EVO M.2. 250GB SSD (QD 4)

Samsung 850 EVO M.2. and mSATA SSD review

At a queue depth of 4, the Samsung 850 EVO mSATA SSD is
outstanding, and finishes this test in second place. The M.2. version is a little
slower, and finishes the test in seventh place.

ADVERTISEMENT

Queue depth 32

Samsung 850 EVO M.2. and mSATA SSD review

Samsung
850 EVO mSATA 500GB SSD (QD 32)

Samsung 850 EVO M.2. and mSATA SSD review

Samsung
850 EVO M.2. 250GB SSD (QD 32)

Samsung 850 EVO M.2. and mSATA SSD review

At 367.07 MB/s, the Samsung 850 EVO mSATA 500GB SSD is
excellent, and finishes this test in seventh place. The lower capacity M.2. SSD
is once again a bit slower, but is still performing well.


IOMeter 4K random write test with fully random data.

This test is exactly the same as the test above except that
the test data is fully random and is therefore much more difficult to compress.
This test was requested as SandForce based SSDs gain a lot of performance by
being able to compress data on the fly. While the above test shows the
SandForce based SSDs in a best case scenario, the following test will show the
SandForce based SSDs in a much more realistic scenario.

Queue depth 4 with fully random data

Samsung 850 EVO M.2. and mSATA SSD review

Samsung 850 EVO mSATA
SSD – 4K random write (QD 4 with fully random data)

Samsung 850 EVO M.2. and mSATA SSD review

Samsung 850 EVO M.2.
SSD – 4K random write (QD 4 with fully random data)

Samsung 850 EVO M.2. and mSATA SSD review

The Samsung 850 EVO SSDs pay no penalty when writing data
which is incompressible.


4K random write queue depth profile

For this test I used various queue depths from 1 – 32 to
give you an idea how this SSD performs at different queue depths. For a normal
desktop user, with lightweight multitasking, the queue depth will rarely rise
above 2. For heavy multitasking, the queue depth is unlikely to rise above a
value of 8.

The results are shown below.

Samsung 850 EVO M.2. and mSATA SSD review

As we can see, the Samsung 850 EVO SSDs have outstanding
performance at low queue depths, but after reaching a queue depth of 4,
performance doesn’t increase with higher queue depths.

Below I present a table of the results in more detail.

Samsung 850 EVO M.2. and mSATA SSD review


IOMeter 4K random read test.

If there are many 4k files created, then that must also mean
that many 4k files need to be read. This test measures 4k reading performance.

It is said that most 4K random reads take place at a queue
depth of only one, and readers have requested that I include this test in my
reviews.

Queue depth 1

Samsung 850 EVO M.2. and mSATA SSD review

Samsung 850 mSATA 500GB
SSD – 4K random read (QD 1)

Samsung 850 EVO M.2. and mSATA SSD review

Samsung 850 M.2.
250GB SSD – 4K random read (QD 1)

Samsung 850 EVO M.2. and mSATA SSD review

In this test the Samsung 850 EVO mSATA and M.2. SSDs have
outstanding performance, and finish in first and third places respectively.

Queue depth 4

Samsung 850 EVO M.2. and mSATA SSD review

Samsung 850 EVO mSATA
500GB SSD – 4K random read (QD 4)

Samsung 850 EVO M.2. and mSATA SSD review

Samsung 850 EVO M.2.
250GB SSD – 4K random read (QD 4)

Samsung 850 EVO M.2. and mSATA SSD review

At a queue depth of four, the Samsung 850 EVO mSATA and M.2.
SSDs are outstanding, and are the third and fourth fastest SSDs in this test.

Queue depth 32                             

Samsung 850 EVO M.2. and mSATA SSD review

Samsung 850 EVO mSATA
500GB SSD – 4K random read (QD 32)

Samsung 850 EVO M.2. and mSATA SSD review

Samsung 850 EVO M.2.
250GB SSD – 4K random read (QD 32)

Samsung 850 EVO M.2. and mSATA SSD review

At a queue depth of 32, the Samsung 850 EVO mSATA and M.2. SSD
are showing outstanding performance, and they are the fifth and sixth fastest
SSDs in this test.

4K random read queue depth profile.

This test shows how the review drive scales with increasing
queue depths.

Samsung 850 EVO M.2. and mSATA SSD review

Below I present a table of the results in greater detail.

Samsung 850 EVO M.2. and mSATA SSD review


IOMeter 512KB sequential write test with repeating data.

Sequential writing performance is also very important; in
this test sequential writing performance is measured.

Samsung 850 EVO M.2. and mSATA SSD review

Samsung 850 EVO mSATA
500GB SSD – 512K Sequential write with repeating data

Samsung 850 EVO M.2. and mSATA SSD review

Samsung 850 EVO M.2.
250GB SSD – 512K Sequential write with repeating data

Samsung 850 EVO M.2. and mSATA SSD review

The Samsung 850 EVO mSATA and M.2. SSDs show an excellent
turn of speed, finishing this test in sixth and eleventh places respectively.

512K sequential write – Queue depth profile

While most sequential writes will rarely rise above a queue
depth of two, it has been noted from SATA analyzer traces that with more
demanding tasks, queue depths can rise very close to a queue depth of four.
This is why I now include queue depth profiles for sequential read and write.

Please note that in the following graph, I do not have the
lowest possible score set at zero. This is purely to allow the graphs to be
easier to read, but starting with a lowest possible score other than zero,
gives the impression that there are large differences between competing SSDs with
regard to performance, so please keep this in mind.  

Samsung 850 EVO M.2. and mSATA SSD review

512K sequential write
– Queue depth profile

Below I present a table of the results in more detail.

Samsung 850 EVO M.2. and mSATA SSD review

IOMeter 512KB sequential write test with fully random data.

This test is almost exactly the same as the test above
except that the test data is fully random in nature. This test was requested as
SandForce based SSDs gain a lot of performance by being able to compress data
on the fly. While the above test shows the SandForce based SSDs in a best case
scenario, the following test will show the SandForce based SSDs in a more
realistic light. In the real world, the data is neither 100% incompressible nor
100% compressible, it is somewhere in between. So please keep this in mind.

Samsung 850 EVO M.2. and mSATA SSD review

Samsung 850 EVO mSATA
500GB SSD – 512K sequential write with fully random data

Samsung 850 EVO M.2. and mSATA SSD review

Samsung 850 EVO M.2.
250GB SSD – 512K sequential write with fully random data

Samsung 850 EVO M.2. and mSATA SSD review

With data that is not so easy to compress, the SandForce SF-2281
based SSDs take a big performance hit, whilst the Samsung 850 EVO mSATA and
M.2. SSDs return a very impressive 530.24 MB/s and 520.19 MB/s respectively.


IOMeter 512KB sequential read test QD1.

This test measures 512k sequential reading performance at
very low queue depths.

Samsung 850 EVO M.2. and mSATA SSD review

Samsung 850 EVO mSATA
500GB SSD – 512K sequential reading test (QD 1)

Samsung 850 EVO M.2. and mSATA SSD review

Samsung 850 EVO M.2.
250GB SSD – 512K sequential reading test (QD 1)

Samsung 850 EVO M.2. and mSATA SSD review

The Samsung 850 EVO mSATA and M.2. SSDs have excellent
sequential reading performance at very low queue depths, finishing in sixth and
seventh places respectively.

IOMeter 512KB sequential read test (dual threaded).

This test measures 512k sequential reading performance QD2.

Samsung 850 EVO M.2. and mSATA SSD review

Samsung 850 EVO mSATA
500GB SSD – 512K sequential reading test (QD 2)

Samsung 850 EVO M.2. and mSATA SSD review

Samsung 850 EVO M.2.
250GB SSD – 512K sequential reading test (QD 2)

Samsung 850 EVO M.2. and mSATA SSD review

At a more realistic queue depth the Samsung 850 EVO mSATA
and M.2. SSDs are still showing outstanding sequential reading performance for SATA
SSDs, and finish this test in seventh and ninth place.

512K sequential read – Queue depth profile

While most sequential reads will rarely rise above a queue
depth of two, it has been noted from SATA analyzer traces that with more
demanding tasks, queue depths can rise very close to a queue depth of four.
This is why I now include queue depth profiles for sequential read and write.

Please note that in the following graph, I do not have the
lowest possible score set at zero. This is purely to allow the graphs to be
easier to read, but starting with a lowest possible score other than zero, gives
the impression that there are large differences between competing SSDs with
regard to performance, so please keep this in mind. 

Samsung 850 EVO M.2. and mSATA SSD review

512K sequential read – Queue depth profile

Below I present a table of the results in greater detail.

Samsung 850 EVO M.2. and mSATA SSD review


IOMeter Workstation simulation (outstanding I/Os = 64).

When running applications you will find that there is a
mixture of small random files and larger sequential files, being created and
read. Not only that, it isn’t just one file at a time. In this test I measure a
simulated workstation pattern, with a queue depth of 64 (threaded).

Samsung 850 EVO M.2. and mSATA SSD review

Samsung 850 EVO mSATA
500GB SSD – Workstation simulation

Samsung 850 EVO M.2. and mSATA SSD review

Samsung 850 EVO M.2.
250GB SSD – Workstation simulation

Samsung 850 EVO M.2. and mSATA SSD review

The ‘workstation’ simulation sorts the men out from the
boys, with its mixed reads and writes. This test shows how an SSD could behave with
a heavy workload, in a graphics, or video workstation environment. The Samsung
850 EVO mSATA SSD has excellent mixed read/write performance, and finishes the
test in third place. The Samsung 850 EVO M.2., with its lower capacity is still
performing well.


Summary

All in all, the Samsung 850 EVO mSATA and M.2, SSDs have
performed extremely well in our IOMeter tests. They both have outstanding
reading and writing performance, with the higher capacity mSATA version excellent
across the board. The Samsung 850 EVO M.2. 250GB SSD with only 3GB of emulated
SLC NAND doesn’t have the sustainable writing performance of the higher
capacity mSATA version, so tends to be a bit slower overall.

 

Now let’s head to the next page where we will look at how
the Samsung 850 EVO SSD performs using a new benchmarking application….

 

ADVERTISEMENT