Crucial MX100 512GB & Samsung 850 Pro 256GB SSDs

Table of Contents

The Crucial MX100 512GB is the ultimate value SSD with the best capacity:price ratio on the market, while the Samsung 850 Pro 256GB is positioned as the latest ultra-fast premium flagship emphasizing performance and reliability.


October 20, 2014 by Lawrence Lee

Crucial MX100 512GB
2.5 inch SSD
Samsung 850 Pro 256GB
2.5 inch SSD
Crucial Technology Samsung
Street Price
US$210 US$190

Crucial and Samsung are two of the biggest names in solid-state drives. Micron,
the company behind the Crucial brand, is a giant in all things memory-related
and has decades of experience in the industry. They’re not the flashiest company,
but they haven’t survived this long by accident. Their products are popular
and generally regarded as reliable and value conscious. Samsung is a huge conglomerate
that lacks Micron’s specialization, but their sheer size and massive manufacturing
base has given them an edge over much of the competition. All the main components
in their SSDs, the NAND Flash, controller, and firmware, are designed and manufactured
in-house, keeping potentially unreliable third parties out of their supply chain
and maximizing their own profit. With this cushion, they can undercut the competition
or invest in better technology.

The strengths of each company are evident in the two drives we’re evaluating
today, the Crucial MX100 and Samsung 850 Pro. The former is positioned as the
ultimate value SSD, with an excellent dollar per byte ratio. The latter is being
pushed as the latest and greatest, the newest addition Samsung’s fleet of high
performance SSDs.

The Crucial MX100 512GB and Samsung 850 Pro 256GB boxes.

The respective drives.

Specifications: Crucial MX100 512GB & Samsung 850 Pro 256GB
Model number CT512MX100SSD1 MZ-7KE256
Interface SATA 6Gb/s
Height 7 mm (w/ 9.5 mm adapter) 7 mm
Controller Marvell 88SS9189 Samsung 3-core MEX
DRAM cache memory 512MB LPDDR2
Sequential Read (max) 550 MB/s
Sequential Write (max) 500 MB/s 520MB/s
4KB Random Read 90,000 IOPS 100,000 IOPS
4KB Random Write 85,000 IOPS 90,000 IOPS
Security AES 256-bit, TCG/Opal v2.0, IEEE1667
Power consumption N/A (not specified) Read (Average) : Max. 3.3W (1TB)
Write (Average) : Max. 3.0W (1TB)
Idle : Max. 0.4W
Device Sleep : 2mW
MTBF 1.5 million hours 2 million hours
Write Endurance 72TB 150TB
Warranty 3 years 10 years

The specifications don’t differentiate the drives much. Both 2.5″ form
factor drives models are 7 mm thick, making them compatible with more ultrabooks
than the typical 9.5 mm fare. They both have 512MB of DDR2 memory acting as
cache, and support the latest modern encryption standards. Both have lofty claims
regard regarding sequential and random performance with the 850 Pro promising
a bit more horsepower. The most interesting difference is cliam durability:
The 850 Pro boosts a longer MTBF, more than double the write endurance despite
being lower capacity, offering an astounding 10 years warranty instead of 3.

The Crucial MX100 is a 7 mm thick drive but also ships with a 9.5 mm adapter bracket. There was also a complimentary key for a copy of Acronis True Image HD 2014 included inside the box.

The MX100 is actually a tweak of an older drive in Crucial’s lineup, the M550,
currently positioned as their upscale consumer SSD. The MX100 features the same
Marvell 88SS9189 controller, but it utilizes more affordable NAND Flash manufactured
with Micron’s smaller 16nm process (most modern drives use 19/20nm technology).
These chips are more densely packed, but this also means fewer NAND packages
working in parallel, one of the main reasons why low capacity SSDs frequently
have less impressive performance compared to larger versions of the same model.

Effectively, they’ve traded reduced performance for more capacity and lower
cost — a perfectly valid strategy often employed to create a budget SSD.
The 512GB model retails for a mere US$210, making it easily the cheapest
big name SSD in the ~500GB range. 128GB and 256GB variants are available are
priced just as attractively. Despite all this, Crucial proudly proclaims that
the MX100 offers not only great value but also “unrelenting performance.”

The Samsung 850 Pro, also a 7 mm thick drive.

The Samsung 850 Pro isn’t a completely new drive either, powered by the same
3-core Samsung MEX controller as the 840
, currently our SSD performance champion. However, its approach to
the actual NAND Flash is completely different than the MX100. Rather than scaling
down with a smaller fabrication process and trying to deal with the resulting
performance complications, they’ve employed what they call V-NAND, effectively
NAND arrayed in three dimensions rather than two. This allows more Flash memory
to be packed inside, freeing Samsung to use 40nm MLC chips, which is unheard
of in today’s SSD climate. With superior technology, Samsung has more physical
space than their competitors to leverage into stronger performance.

Also available in 128GB, 512GB, and 1TB versions, the 850 Pro carries a healthy
price premium across the board, with the 256GB model selling for about US$190.
It’s quite expensive but not unreasonable if you take into account the reliability
and performance claims. Samsung has one last ace up their sleeve: “RAPID
mode.” Enabling this feature in their Magician software allows the SSD
to use up to 25% of the system’s memory as an ultra-fast cache. RAMDisk users
are familiar with this concept, creating a virtual drive out of excess RAM for
frequently accessed applications, but RAPID mode does it all automatically under
the hood.


Our samples were tested according to our standard
hard drive testing methodology
. As of mid-2008, we have been conducting
most acoustics tests in our
own 10~11 dBA anechoic chamber
, which results in more accurate, lower SPL
readings than before, especially with sub-20 dBA@1m devices.

Two forms of hard drive noise are measured:

  1. Airborne acoustics
  2. Vibration-induced noise.

These two types of noise impact the subjective
perception of hard drive noise differently depending on how and where the drive
is mounted.

Both forms of noise are evaluated objectively and
subjectively. Airborne acoustics are measured in our anechoic chamber using a lab reference
microphone and computer audio measurement system
. Measurements are taken at a distance of one meter from the top
of the drive using an A-weighted filter. Vibration noise is rated on a scale
of 1-10 by comparing against our standard reference drives.

As of late-2011, we have been conducting performance testing. A combination of timed real-world tests is used to represent a workload of common activities for a boot drive including loading games, running disk-intensive applications, copying files, and installing programs. Synthetic tests are also run to better judge the performance across the entire span of the drive.

Summary of primary HDD testing tools:

Key Components in LGA1155 Heatsink Test Platform:

Real World Performance Test Tools:

Real World Benchmark Details:

  • Boot: Time elapsed between pressing the power button to the desktop and the Windows start sound playing (minus the time for an average SSD to get to the “loading Windows” screen, 12 seconds on our test system)
  • COD5: Combined load time for the “Breaking Point” and “Black Cats” levels.
  • Far Cry 2: Load time for one level.
  • ExactFile: Creating a MD5 check file of our entire test suite folder.
  • TrueCrypt: Creating a 10GB encrypted file container.
  • 3DMark Vantage: Install time, longest interval between prompts.
  • PowerDVD 10: Install time, longest interval between prompts.
  • Small File Copy: Copy time for a variety of small HTML, JPEG, MP3, ZIP, and EXE files.
  • Large File Copy: Copy time for 4 AVI files, 2 x 700MB and 2 x 1400MB
    in size.

A final caveat: As with most reviews, our comments
are relevant to the samples we tested. Your sample may not be identical. There
are always some sample variances, and manufacturers also make changes without
telling everyone.

Ambient conditions at time of testing were 10.5 dBA and 20~23°C.

Synthetic Performance

We start off with synthetic tests results. They don’t tell the whole story of course, but it’s a quick and dirty way of gauging relative performance between drives and of course, it’s easily reproducible by our readers at home.

HD Tune

HD Tune main benchmark result: Crucial MX100 512GB.

HD Tune main benchmark result: Samsung 850 Pro 256GB.


The Samsung 850 Pro barely edged out the 840 Pro in sequential transfer speed to take the top spot while the MX100 had a middling result. Both drives exhibited low latency with best in show access times but the MX100 came out ahead. It would seem the two drives are extremely responsive, even by SSD standards.


CrystalDiskMark benchmark results. Crucial MX100 512GB on the left, Samsung 850 Pro 256GB on the right.


Unusually, the 850 Pro and MX100 showed a bias towards reading over writing with the larger 512K block size, but both results were strong, well over 400 MB/s, surpassing many of the other models compared. For most system functions, random performance with the smaller 4K block size is more relevant as operating systems frequently read/write scattered small files during operation. Here, the two drives were more average, with the MX100 again showing preference for writes while the 850 Pro took a more balanced approach.

Real World Performance

Our real world performance testing begins with a Windows 7 image, loaded with our test suite, being cloned to a 50GB partition
at the beginning of each drive. The suite is run start to finish three times with a defragmentation (except for SSDs and hybrid drives) and reboot
between runs.
Average times were collected for comparison. For these tests, we also tried out the Samsung 850 Pro in RAPID mode.




In many of the tests, the MX100 came in near the bottom, but only by fractions of a second in most cases. Also keep in mind the field is composed of the the fastest SSDs we’ve reviewed thus far. Boot time and file copying was where the MX100 truly excelled, and by a significant margin over most of the competition.

The 850 Pro placed in the top three of every testing category, and performing especially strong in the file copy tests. Enabling RAPID mode resulted in some marked improvement in the loading and file copy tests, but there was also a negative effect in the application and installation tests. Overall, the impact was positive but we didn’t see enhanced performance across the board. There was also a slightly extended boot delay, possibly because Samsung’s Magician software had to load on startup.

To get a sense of the overall performance of the drives, we’ve given each model a proportional score in each real world benchmark series (loading, application, file copying, and installation), with each set equally weighted. The scale has been adjusted with the MX100 512GB as the reference point at 100 points.

With this scoring system, the MX100 comes out in front of most of the field
thanks primarily to a strong showing in the file copy tests. It didn’t surpass
the Samsung 840 Pro, however, while the 850 Pro squeaked past its predecessor
by two points. RAPID mode somehow negatively impacted the 850 Pro in a few of
the tests, but dramatic gains in other areas provided an overall improvement
of 2%. Note that this was with 4GB of RAM only, so only 1GB was reserved for
RAPID mode. Gains could be much higher with more system memory installed.

Power Consumption

Energy efficiency was mixed bag for the two drives. Strangely, the MX100 used
almost the same amount of power idling as it did during random read seek test.
The idle figure is surprisingly high while the seek figure is shockingly low.
The 850 Pro had similar idle consumption to its predecessors, but there was
a 70% increase when seeking. The MX100 apparently is more efficient as an primarily
active drive, while the 850 Pro is more thrifty when inactive.


As solid state drives have no spinning platters or moving parts of any kind,
they are effectively silent storage devices. It is possible that there could
be a tiny bit of electronic noise (typically a high pitched squeal) being emitted,
either intermittently depending on task, or continuously, but neither the MX100
or 850 Pro samples made so much as a peep.


Crucial MX100 512GB

The most striking thing about the Crucial MX100 512GB is its price of just
US$210. At $0.41/GB, it offers the best value on the SSD market today
in the ~500GB capacity range (the 128GB and 256GB models are also priced similarly).
Despite the aggressive pricing, it doesn’t perform like a cut-rate drive, posting
excellent results in our real world performance tests, only surpassed by Samsung’s
840 Pro and 850 Pro 256GB.
It’s a fantastic best bang-for-your-buck SSD, a definite plus considering SSDs
still carry a hefty premium over mechanical hard drives.

The only thing we can really criticize is its idle power consumption. It uses
just over 1W when inactive, which is two to three times more than a typical
SSD. This is negligible in a desktop system, but as a 7 mm thick drive, it’s
obviously a viable option for an ultrabook drive replacement. For notebooks
that sit idle for long stretches of time, the MX100 won’t improve battery life.
On the other hand, its power consumption during random reads was quite low,
so if the mobile machine is constantly being used, run time might be extended

Samsung 850 Pro 256GB

As unlikely as it seems, every time we receive a new Samsung SSD for evaluation,
it performs better than its predecessor, raising the bar for all other SSDs
in the process. The 850 Pro 256GB took first place in our real world performance
tests, giving Samsung a streak of three consecutive victories. The only disappointment
is the margin of improvement — the 850 Pro isn’t as much a step up as the
840 Pro was over the 830.
However, if you have some excess system memory, Samsung’s RAPID mode is capable
of leveraging that extra RAM to give the 850 Pro a small boost, extending its
lead even farther.

The 850 Pro 256GB is currently selling for US$190, making it almost
twice as expensive per byte as the MX100. This would be outrageous based on
performance alone, but you’re not just paying for an extra peppy drive. Its
specified 150TB write endurance is more than double that of the MX100 512GB.
This translates to 42GB of data written to the drive every day for the duration
of the warranty period, an incredible 10 years. Sure, it may not keep up with
new competitors in three or four years time, and become obsolete after five
or six, but it’s still nice to see a manufacturer back up their rhetoric in
writing, especially a flagship product.

Many thanks to Crucial Technology for the Crucial MX100 512GB and Samsung for the 850 Pro 256GB solid-state drive samples.

The Crucial MX100 512GB receives the SPCR Editor’s Choice Award

The Samsung 850 Pro 256GB is recommended by SPCR

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SPCR Articles of Related Interest:
WD Red 6TB and 1TB (2.5-inch) Hard Drives
Seagate Enterprise Class v4 6TB Hard Drive
Samsung 840 Pro 256GB SSD
Seagate NAS HDD 4TB
Western Digital Red 4TB & Se 4TB Hard Drives
ADATA XPG SX300 128GB & Intel 525 Series 180GB mSATA SSDs

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