Corsair Neutron GTX 240GB 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.

The things that I will look at are the total I/O per second and
total MB/s.

Partition alignment and sector boundaries

Windows 7 and 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 will use 4k boundaries if it can. The Corsair
Neutron GTX 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.

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 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.

Queue depth 1

Corsair Neutron GTX 240GB SSD Review
Corsair Neutron GTX SSD – 4K random write (QD1)

Corsair Neutron GTX 240GB SSD Review

At 129.09 MB/s the Corsair Neutron GTX is showing excellent
performance at this queue depth, and is the third fastest SSD in this test.

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

Corsair Neutron GTX 240GB SSD Review
Corsair Neutron GTX (Queue depth 4)

Corsair Neutron GTX 240GB SSD Review

At a queue depth of 4, the Corsair Neutron GTX performance
is very strong indeed, and once again finishes the test in third place.

Queue depth 32

Corsair Neutron GTX 240GB SSD Review
Corsair Neutron GTX (Queue depth 32)

Corsair Neutron GTX 240GB SSD Review

The Neutron GTX is showing exceptional performance at this
queue depth, and is the fastest SSD in this test.


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

Corsair Neutron GTX 240GB SSD Review
Corsair Neutron GTX SSD – 4K random write (QD4 with fully random data)

Corsair Neutron GTX 240GB SSD Review

The SandForce SF-2281 based SSDs pays a big penalty when
having to deal with data that isn’t so easy to compress. The LAMD controller
onboard the Neutron GTX pays no such penalty, and finishes the test in third
place.


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 for 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 result is below.

Corsair Neutron GTX 240GB SSD Review

The Corsair Neutron GTX has the highest peak performance
among the SSDs on test, however it only reaches this level of performance at
very high queue depths. The Everest 2 based SSDs reach peak performance at much
lower queue depths, so it would fair to say that the Neutron GTX, overall, is
just behind the two Everest 2 based SSDs.

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

Corsair Neutron GTX 240GB 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

Corsair Neutron GTX 240GB SSD Review
Corsair Neutron GTX SSD (Queue depth 1)

Corsair Neutron GTX 240GB SSD Review

The Corsair Neutron GTX is performing very well in this
test, and finishes the test in third place.

Queue depth 4

Corsair Neutron GTX 240GB SSD Review
Corsair Neutron GTX SSD (Queue depth 4)

Corsair Neutron GTX 240GB SSD Review

With a higher queue depth the Neutron GTX really starts to
motor, and finishes this test in second place.

Queue depth 32

Corsair Neutron GTX 240GB SSD Review
Corsair Neutron GTX SSD (Queue depth 32)

Corsair Neutron GTX 240GB SSD Review

With a high queue depth the Neutron GTX is performing
exceptionally well, and is the fastest SSD in this test.

4K random read queue depth profile.

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

Corsair Neutron GTX 240GB SSD Review

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

Corsair Neutron GTX 240GB SSD Review

If we look at the Corsair Neutron GTX 4K random read
performance in detail, it is quite similar to the Vertex 4. The OCZ Vertex 4 is
slightly faster at lower queue depths and the Corsair Neutron GTX is faster at
higher queue depths. Let’s call it a draw.


IOMeter 512KB write test with repeating data.

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

Corsair Neutron GTX 240GB SSD Review

Corsair Neutron GTX 512K
Sequential write with repeating data

Corsair Neutron GTX 240GB SSD Review

The Corsair Neutron GTX has good sequential writing
performance, but with data that is easily compressed by the SandForce based
SSDs, it can’t quite keep pace with them. However, it is quite a bit faster
than the two Everest 2 based SSDs.

IOMeter 512KB write test with fully random data.

This test is 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.

Corsair Neutron GTX 240GB SSD Review
Corsair Neutron GTX SSD – 512K sequential write with fully random data

Corsair Neutron GTX 240GB SSD Review

With data that is not so easy to compress, the SandForce SF-2281
based SSDs take a big hit in performance, and the Neutron GTX is by quite some
margin the fastest SSD in this test. In fact it’s the first SSD to break the
500MB/s barrier when writing fully random data.


IOMeter 512KB sequential read test QD1.

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

Corsair Neutron GTX 240GB SSD Review
Corsair Neutron GTX SSD – 512K sequential reading test QD1

Corsair Neutron GTX 240GB SSD Review

The Corsair Neutron GTX is showing very good performance at
low depths in this test, and finishes the test in fourth place.

IOMeter 512KB sequential read test (dual threaded).

This test measures 512k sequential reading performance QD2.

Corsair Neutron GTX 240GB SSD Review
Corsair Neutron GTX SSD – 512K sequential reading test QD2

Corsair Neutron GTX 240GB SSD Review

At a more realistic queue depth the Corsair Neutron GTX is
showing excellent sequential reading performance, and quite comfortably the
fastest SSD in this test.


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).

Corsair Neutron GTX 240GB SSD Review
Corsair Neutron GTX SSD – Workstation simulation

Corsair Neutron GTX 240GB SSD Review

There is always something that throws a spanner in the works
and turns out an unexpected result, and this was it. Having confirmed the
result by running the test another couple of times, I started to ponder why the
Neutron GTX is not performing so well in this test. When I looked at the
"workstation profile" I found that although we are dealing with very
high queue depths, there is a lot of "high queue depths" with
sequential reading and writing. It’s clear that at lower queue depths when
regarding sequential reading and writing the Neutron GTX is very fast, but at
higher queue depths, the Neutron GTX is not quite as strong.

In any case, it is very unlikely that a mainstream user will
come across this type of work pattern, so one should not be concerned.


Summary

Overall the Corsair Neutron GTX SSD has done extremely well
in the IOMeter tests. It has very strong random reading and writing
performance, and the same can be said for sequential performance. What is clear
from these results is the Neutron GTX can’t hide its enterprise performance
profile. Remember, the LAMD SSD processor’s heritage lies in the enterprise
performance profile segment of the SSD market.

Nonetheless, the Corsair Neutron GTX is clearly a very
strong performer, and it will be interesting to see if this performance carries
forward to the real world.  

Now let’s head to the next page where we will look at how
the Corsair Neutron GTX SSD performs using a brand new benchmarking
application….