Samsung 840 Pro Solid State Drive Review

By Hank Tolman

Manufacturer: Samsung
Product Name: Samsung 840 Pro SSD
Model Number: MZ-7PD256BW (512GB), MZ-7PD512BW (512GB)
Price As Tested: 256GB: $204 (Amazon | Newegg), 512GB: $390 (Amazon | Newegg)

Full Disclosure: The product sample used in this article has been provided by Samsung.

For going on two years now, Samsung has been a major player in the SSD market. Before that, Samsung SSDs just didn’t compete. That has all changed with the Samsung 800 series of SSDs and even more recently with the release of Samsung’s RAPID technology for use with Samsung 840 SSDs. Samsung now competes at the top of the market and their SSDs are forces to be reckoned with. In this article, Benchmark Reviews looks at the Samsung 840 Pro SSD’s performance, with and without RAPID mode enabled.

By all rights, Samsung should be at the top of the market. Samsung is the biggest manufacturer of flash memory in the world. While it is true that most of that memory goes to other companies, Samsung is making more and more of their own consumer products. The Samsung 840 series of SSDs includes the 840, the 840 Pro, and the 840 EVO.

Not only does Samsung make their own flash, they also make their own SSD controllers and their own firmware. Those three make up all the components necessary for a Solid State Drive. Typical SSD producers may not actually manufacture any of those three components. A lot of SandForce SSDs fall into this category. Other companies might produce just their own firmware, or their own flash memory, or even their own controller. Crucial, owned by Micron, falls into the category of a manufacturer that uses their own memory. OCZ makes their own SSD controller.

Samsung makes it all; the memory, the controller, and the firmware. That gives Samsung a distinct advantage. They can make changes or adjustments to whatever part of the manufacturing process makes the most sense, rather than trying to work with what someone else has made. While the first iteration of Samsung SSDs didn’t get very high marks, that ability to improve has pushed Samsung up the ranks during recent releases. The Samsung 830 SSD received very high marks all around. I expect similar performance from the Samsung 840 Pro, and even better marks with RAPID mode enabled.

Benchmark Reviews Executive Editor, Olin Coles, provides an excellent overview in the sections below:
Despite decades of design improvements, the hard disk drive (HDD) is still the slowest component of any personal computer system. Consider that modern desktop processors have a 1 ns response time (nanosecond = one billionth of one second), while system memory responds between 30-90 ns. Traditional hard drive technology utilizes magnetic spinning media, and even the fastest spinning mechanical storage products still exhibit a 9,000,000 ns / 9 ms initial response time (millisecond = one thousandth of one second). In more relevant terms, the processor receives the command and must then wait for system memory to fetch related data from the storage drive. This is why any computer system is only as fast as the slowest component in the data chain; usually the hard drive.

In a perfect world all of the components operate at the same speed. Until that day comes, the real-world goal for achieving optimal performance is for system memory to operate as quickly as the central processor and then for the storage drive to operate as fast as memory. With present-day technology this is an impossible task, so enthusiasts try to close the speed gaps between components as much as possible. Although system memory is up to 90x (9000%) slower than most processors, consider then that the hard drive is an added 1000x (100,000%) slower than that same memory. Essentially, these three components are as different in speed as walking is to driving and flying.

Solid State Drive technology bridges the largest gap in these response times. The difference a SSD makes to operational response times and program speeds is dramatic, and takes the storage drive from a slow ‘walking’ speed to a much faster ‘driving’ speed. Solid State Drive technology improves initial response times by more than 450x (45,000%) for applications and Operating System software, when compared to their mechanical HDD counterparts. The biggest mistake PC hardware enthusiasts make with regard to SSD technology is grading them based on bandwidth speed. File transfer speeds are important, but only so long as the operational I/O performance can sustain that bandwidth under load.
As we’ve explained in our SSD Benchmark Tests: SATA IDE vs AHCI Mode guide, Solid State Drive performance revolves around two dynamics: bandwidth speed (MB/s) and operational performance I/O per second (IOPS). These two metrics work together, but one is more important than the other. Consider this analogy: bandwidth determines how much cargo a ship can transport in one voyage, and operational IOPS performance is how fast the ship moves. By understanding this and applying it to SSD storage, there is a clear importance set on each variable depending on the task at hand.

For casual users, especially those with laptop or desktop computers that have been upgraded to use an SSD, the naturally quick response time is enough to automatically improve the user experience. Bandwidth speed is important, but only to the extent that operational performance meets the minimum needs of the system. If an SSD has a very high bandwidth speed but a low operational performance, it will take longer to load applications and boot the computer into Windows than if the SSD offered a higher IOPS performance.

Samsung created a winner with the 830 SSD, but they haven’t been sitting back on their laurels. Samsung updated the successful MCX controller to a new controller, called MDX. Samsung also switched ARM cores from the ARM9 cores used in the 830 to three ARM Cortex-R4 cores in the 840 and 840 Pro SSDs. The R4 cores also run at a clockspeed of 300MHz, quite an increase over the 220MHz clockspeed on the 830 SSD. The 840 and 840 Pro SSDs use Toggle Mode 2.0 memory interface, rated at up to 400Mbps and manufactured on a 21nm node. The old 830 SSD used Toggle Mode 1.0 NAND at up to 133Mbps, making the 840 interface roughly three times faster.

While the 840 and the 840 Pro both use the MDX controller, which boasts advanced geometry and lower power consumption, they use different flash memory. The Samsung 840 Pro SSD uses Samsung’s proven Toggle Mode MLC Flash memory. The 840 SSD, on the other hand, opts for the slower and less expensive, albeit newer Triple-Level Cell (TLC) NAND flash.

The Samsung 840 Pro SSD comes in 128GB, 256GB, and 512GB flavors currently, with a possible 64GB version coming along in the future. Since the 840 Pro is intended more for a commercial and possibly enthusiast market when compared to the 840 or 840 EVO, the 64GB version doesn’t really make as much sense.

The 256GB and 512GB models of the 840 Pro contain a 512MB of LPDDR2-1066 cache. The 128GB model has 256MB of cache. The cache, at 1066MHz is another upgrade from the 256MB of LPDDR2-800 cache on the 830 SSD. The 840 Pro also houses another handy little upgrade in the form of full drive encryption via AES-256.

The Samsung 840 Pro SSD is adorned with a flat, black, matted finish. Other than that, it looks just like previous Samsung SSDs, unadorned with anything besides the Samsung logo and an orange square patch. Well, there is also a tiny arrow pointing you toward the SATA connections. The 840 Pro SSD comes in the now-standard 2.5” 7mm form factor. That size will fit current laptops, but you may need an adapter if your laptop is older and requires a 9mm drive.

The biggest news regarding the Samsung 840 Pro, however, it its relatively recent adoption into the family of Samsung SSDs that support RAPID mode. RAPID mode is very impressive, and warrants a closer look.

RAPID stands for Real-time Accelerated Processing of I/O Data and it starts speeding up your reads and writes as soon as it is enabled. RAPID mode is designed to improve random I/O performance for small sizes of data at low queue depths. The icing on the cake, however, is that RAPID mode tries to analyze application and data usage in order to optimize I/O for frequently used data, which they call ‘hot data’.

RAPID mode analyzes all storage related activity by inserting itself as a filter driver in the Windows storage stack. By analyzing all storage-related activity, RAPID mode can grab hold of spare resources in the form of RAM to cache the ‘hot data’ it has identified, thus greatly improving read performance. RAPID mode also tries to optimize write performance by closely controlling the coordination between the CPU and the SSD.

RAPID mode actually acts similarly to your system cache, and its main function doesn’t even deal with the SSD at all. Unlike the system cache, though, that just stores recently accessed data, RAPID mode provides RAM caching based on a number of factors, like access frequency, file types, system status, and RAM availability. RAPID mode also caches the ‘hot data’ across sessions and reboots.

RAPID mode optimizes write performance by identifying the frequent micro-transactions that take place quite often behind the scenes, like log updates or indexing. RAPID mode looks for low-queue-depth random write requests and flags them to be combined together into a single, larger, higher queue-depth request and written in parallel across the available NAND die. Since SSDs favor parallel processing, this action can greatly reduce the time required to complete all those individual micro-transactions.
Source: Samsung

Type	Product Type Solid State Drive	Design 2.5″ 7mm (Ultraslim) Form Factor	Series 840 PRO
Storage	Capacity 512GB; 256GB; 128GB
Features	Sequential Read Up to 540MB/s	Sequential Write Up to 520MB/s	Random Read Up to 100K IOPS	Random Write Up to 90K IOPS
General	Power Consumption (W) .15W
Operating Systems	Compatible Windows Vista or Later
Environmental Specs	Operating Temps 32ᵒF to 140ᵒF
Weight	Product .15 lb
Warranty	Product 5 Years
Product Contents	Samsung SmartMigration Software	Samsung Software & Manual CD	Quick User Manual

Solid State Drives have traveled a long winding course to finally get where they are today. Up to this point in technology, there have been several key differences separating Solid State Drives from magnetic rotational Hard Disk Drives. While the DRAM-based buffer size on desktop HDDs has recently reached 64 MB and is ever-increasing, there is still a hefty delay in the initial response time. This is one key area in which flash-based Solid State Drives continually dominates because they lack moving parts to “get up to speed”.

However the benefits inherent to SSDs have traditionally fallen off once the throughput begins, even though data reads or writes are executed at a high constant rate whereas the HDD tapers off in performance. This makes the average transaction speed of a SSD comparable to the data burst rate mentioned in HDD tests, albeit usually lower than the HDD’s speed.

Comparing a Solid State Disk to standard Hard Disk Drives is always relative; even if you’re comparing the fastest rotational spindle speeds. One is going to be many times faster in response (SSDs), while the other is usually going to have higher throughput bandwidth (HDDs). Additionally, there are certain factors which can affect the results of a test which we do our best to avoid.
Early on in our SSD coverage, Benchmark Reviews published an article which detailed Solid State Drive Benchmark Performance Testing. The research and discussion that went into producing that article changed the way we now test SSD products. Our previous perceptions of this technology were lost on one particular difference: the wear leveling algorithm that makes data a moving target. Without conclusive linear bandwidth testing or some other method of total-capacity testing, our previous performance results were rough estimates at best.

Our test results were obtained after each SSD had been prepared using DISKPART or Sanitary Erase tools. As a word of caution, applications such as these offer immediate but temporary restoration of original ‘pristine’ performance levels. In our tests, we discovered that the maximum performance results (charted) would decay as subsequent tests were performed. SSDs attached to TRIM enabled Operating Systems will benefit from continuously refreshed performance, whereas older O/S’s will require a garbage collection (GC) tool to avoid ‘dirty NAND’ performance degradation.

It’s critically important to understand that no software for the Microsoft Windows platform can accurately measure SSD performance in a comparable fashion. Synthetic benchmark tools such as ATTO Disk Benchmark and Iometer are helpful indicators, but should not be considered the ultimate determining factor. That factor should be measured in actual user experience of real-world applications. Benchmark Reviews includes both bandwidth benchmarks and application speed tests to present a conclusive measurement of product performance.

• Motherboard: ASUS A88X Pro FM2+
• Processor: AMD A10-7850K APU
• System Memory: 8GB AMD Radeon DDR3 2400MHz
• PSU: Corsair CMPSU-850TX 850W 80-Plus Certified
• Operating System: Microsoft Windows 7 Professional 64-Bit with Service Pack 1

The following storage hardware has been used in our benchmark performance testing, and may be included in portions of this article:

• Samsung 840 Pro SSD MZ-7PD512BW
• Crucial m4 CT256M4SSD2 256GB SATA 6Gb/s MLC SSD
• Corsair Force LS CSSD-F240GBLS
• Intel SSD 530 Series MLC Solid State Drive
• OCZ Vertex 4 VTX4-25SAT3-256G MLC SSD

• AS SSD Benchmark 1.6.4067.34354: Multi-purpose speed and operational performance test
• ATTO Disk Benchmark 2.46: Spot-tests static file size chunks for basic I/O bandwidth
• CrystalDiskMark 3.0.1a by Crystal Dew World: Sequential speed benchmark spot-tests various file size chunks
• Iometer 1.1.0 (built 08-Nov-2010) by Intel Corporation: Tests IOPS performance and I/O response time
• Finalwire AIDA64: Disk Benchmark component tests linear read and write bandwidth speeds

This article utilizes benchmark software tools to produce operational IOPS performance and bandwidth speed results. Each test was conducted in a specific fashion, and repeated for all products. These test results are not comparable to any other benchmark application, neither on this website or another, regardless of similar IOPS or MB/s terminology in the scores. The test results in this project are only intended to be compared to the other test results conducted in identical fashion for this article.

Alex Schepeljanski of Alex Intelligent Software develops the free AS SSD Benchmark utility for testing storage devices. The AS SSD Benchmark tests sequential read and write speeds, input/output operational performance, and response times.

AS-SSD Benchmark uses compressed data, so sequential file transfer speeds are reported lower than with other tools using uncompressed data. Even so, the Samsung 840 Pro comes right out of the gate with sequential reads over 500 MB/s and sequential write speeds approaching that mark. The real surprise, though, are the numbers that the 840 Pro achieves in RAPID mode.

With RAPID mode enabled through Samsung Magician, the Samsung 840 Pro SSD reaches for the starts. Sequential read speeds are above 1 GB/s with RAPID mode enabled and sequential write speeds are over 800 MB/s. That’s a pretty decisive start for the 840 Pro in our testing and if the AS-SSD tests are an indicator, the rest of the SSDs in our bench are about to be left in the dust.

In the next section, Benchmark Reviews tests transfer rates using ATTO Disk Benchmark.

The ATTO Disk Benchmark program is free, and offers a comprehensive set of test variables to work with. In terms of disk performance, it measures interface transfer rates at various intervals for a user-specified length and then reports read and write speeds for these spot-tests. There are some minor improvements made to the 2.46 version of the program that allow for test lengths up to 2GB, but all of our benchmarks are conducted with 256MB total length. ATTO Disk Benchmark requires that an active partition be set on the drive being tested. Please consider the results displayed by this benchmark to be basic bandwidth speed performance indicators.
Our bandwidth speed tests begin with the Samsung 840 Pro solid state drive attached to the AMD FM2+ SATA 6Gb/s controller operating in AHCI mode. Using the ATTO Disk Benchmark tool, the test drive performs basic file transfers ranging from 0.5 KB to 8192 KB.

The Samsung 840 Pro SSD reaches the top of its read game at around 128 KB file chunks and tops out at just over 563 MB/s at 2048 KB file size. The write results tell a similar story, topping out at 516 MB/s. The results put the Samsung 840 Pro at the top of the charts, and that is before we enabled RAPID mode. As was the case in the AS-SSD results, RAPID mode just makes the difference silly.

In the next section, Benchmark Reviews tests sequential performance using the CrystalDiskMark 3.0 software tool…

CrystalDiskMark 3.0 is a file transfer and operational bandwidth benchmark tool from Crystal Dew World that offers performance transfer speed results using sequential, 512KB random, and 4KB random samples. For our test results chart below, the 4KB 32-Queue Depth read and write performance was measured using a 1000MB space. CrystalDiskMark requires that an active partition be set on the drive being tested, and all drives are formatted with NTFS on the Intel P67 chipset configured to use AHCI-mode. Benchmark Reviews uses CrystalDiskMark to illustrate operational IOPS performance with multiple threads. In addition to our other tests, this benchmark allows us to determine operational bandwidth under heavy load.

If you have gotten used to the Samsung 840 Pro sitting on top of the charts, then the CrystalDisk Mark scores come as no surprise to you. The results speak for themselves, and once again, RAPID mode puts the 840 Pro on a Virgin Airways flight.

In the next section, we continue our testing using Iometer to measure input/output performance…

Iometer is an I/O subsystem measurement and characterization tool for single and clustered systems. Iometer does for a computer’s I/O subsystem what a dynamometer does for an engine: it measures performance under a controlled load. Iometer was originally developed by the Intel Corporation and formerly known as “Galileo”. Intel has discontinued work on Iometer, and has gifted it to the Open Source Development Lab (OSDL). There is currently a new version of Iometer in beta form, which adds several new test dimensions for SSDs.

Iometer is both a workload generator (that is, it performs I/O operations in order to stress the system) and a measurement tool (that is, it examines and records the performance of its I/O operations and their impact on the system). It can be configured to emulate the disk or network I/O load of any program or benchmark, or can be used to generate entirely synthetic I/O loads. It can generate and measure loads on single or multiple (networked) systems.

For 4K Aligned 4KB Random Read testing, the Samsung 840 Pro once again leads the pack. The OCZ Vertex 4 comes pretty close, but the real surprise to me in this test was the Corsair Force LS.

The 4K Aligned 4KB Random Write tests give us our first test where the Samsung 840 Pro doesn’t top the chart. The OCZ Vertex 4 beats out the 840 Pro by a narrow margin. That is, of course, before we enabled RAPID mode. Nothing holds a candle to the 840 Pro with RAPID mode enabled.

Next up here we have the Sequential Read results and the Samsung 840 Pro once again takes second chair, this time to the Corsair Force LS.

The sequential write tests, like the random write test, goes to the OCZ Vertex 4. That is, of course, unless you enable RAPID mode.

In our next section, we test linear read and write bandwidth performance and compare its speed against several other top storage products using EVEREST Disk Benchmark. Benchmark Reviews feels that linear tests are excellent for rating SSDs, however HDDs are put at a disadvantage with these tests whenever capacity is high.

Many enthusiasts are familiar with the Finalwire AIDA64 benchmark suite (formerly Lavalys EVEREST), but very few are aware of the Disk Benchmark tool available inside the program. The AIDA64 Disk Benchmark performs linear read and write bandwidth tests on each drive, and can be configured to use file chunk sizes up to 1MB (which speeds up testing and minimizes jitter in the waveform). Because of the full sector-by-sector nature of linear testing, Benchmark Reviews endorses this method for testing SSD products, as detailed in our Solid State Drive Benchmark Performance Testing article. However, Hard Disk Drive products suffer a lower average bandwidth as the capacity draws linear read/write speed down into the inner-portion of the disk platter. AIDA64 Disk Benchmark does not require a partition to be present for testing, so all of our benchmarks are completed prior to drive formatting.

The Linear Transfer Bandwidth results show us a similar story. This time, though, the Intel SSD 530 takes the number one spot in the write tests. In any event, Samsung has a real winner on their hands with the 840 Pro SSD, especially with their release of RAPID mode through the Samsung Magician utility.

In the next section, I’ll give you my conclusion for the Samsung 840 Pro SSD.

IMPORTANT: Although the rating and final score mentioned in this conclusion are made to be as objective as possible, please be advised that every author perceives these factors differently at various points in time. While we each do our best to ensure that all aspects of the product are considered, there are often times unforeseen market conditions and manufacturer changes which occur after publication that could render our rating obsolete. Please do not base any purchase solely on our conclusion, as it represents our product rating specifically for the product tested which may differ from future versions. Benchmark Reviews begins our conclusion with a short summary for each of the areas that we rate.

In terms of performance, the Samsung 840 Pro SSD is quite the little animal. The 840 Pro consistently scores near or at the top of the charts, easily beating out most of the drives in our test bench and coming very close when it is not the winner. The 840 Pro represents the culmination of a dramatic turn-around in Samsung’s SSD line-up. Making their SSDs from start to finish has allowed Samsung to put together a definite winner in the Samsung 840 Pro SSD.

The Samsung 840 Pro SSD performs splendidly under normal circumstances, but that isn’t even all that the 840 Pro has to offer. When paired with Samsung’s Magician software and with RAPID mode enabled, the 840 Pro goes from the top of the charts to far and above the fastest SSD in our bench.

The Samsung 840 Pro SSD doesn’t exactly reach out and grab you in terms of visual appeal. The device is a simple, matte-black box with nothing flashy at all. The 840 Pro SSD has the words “ Samsung Solid State Drive” on top, along with an orange square and a tiny triangle. In reality, SSDs don’t need any visual appeal. Even in computer chassis that have a viewing window, the hard drives are normally mounted horizontally in cages. SSDs are either mounted in the HDD cages or on the bottom, back, or sides of the chassis. The point is, you are unlikely to ever look at this SSD after it gets put in your case. One could argue that the lack of visual stimulation on an SSD is a good thing, since painting a pretty picture on it would cost more money. That cost would inevitably be passed onto the consumer.

One of the best features of any Solid State Drive is solid construction concept. The lack of mechanical components via the use of flash memory makes SSDs impervious to most forms normal physical damage that would threaten a mechanical Hard Disk Drive. Falls, bumps, and drops aren’t concerning anymore. You also don’t have to worry about the control arm giving out and scratching the platters. That frightening clicking that immediately sends us into a back-up frenzy is out of the question.

Samsung’s 840 Pro SSD definitely maintains all of the well-balanced construction features of every other Solid State Drive, but they also add additional protection in the form of a completely metal housing. Also, while most SSD failures end up happening due to component defects, Samsung mitigates this risk by producing all of the components for the 840 SSD in house. They don’t have to rely on another company to ensure that all of the pieces work properly.

As of June 2014, the Samsung 840 Pro SSD is available in the following capacities and retail prices:

• 128GB: MZ-7PD128BW $110 (Amazon | Newegg)
• 256GB: MZ-7PD256BW $204 (Amazon | Newegg)
• 512GB: MZ-7PD512BW $390 (Amazon | Newegg)

The Samsung 840 Pro SSD is marketed as a commercial product, with the 840 SSD and the 840 EVO Series in the consumer market. Based on our Iometer testing, you can certainly see why the 840 Pro SSD is commercial product. That being said, it will work just fine in any situation. The prices have fallen quite a bit since the launch of the 840 Pro line of SSDs, and that’s good news. With the prices listed above, the Samsung 840 Pro SSDs are worth taking a look at. The 840 Pro did perform at the top of our charts in every test and with RAPID mode enabled, there is no question that they are worth every penny. Of course, the 840 EVO Series SSDs can also use RAPID mode and cost a lot less.
+ RAPID Mode
+ Full drive 256-bit AES hardware encryption
+ Lightweight compact storage solution
+ Resistant to extreme shock impact
+ Excellent Performance
– A little pricey

• Performance: 9.50
• Appearance: 9.00
• Construction: 9.50
• Functionality: 9.50
• Value: 8.00

Excellence Achievement: Benchmark Reviews Golden Tachometer Award.

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