Samsung 840 pro price: 256GB SAMSUNG 840 Pro Series 2.5″ SATA III SSD

Samsung SSD 840 Pro (256GB) Review

by Anand Lal Shimpion September 24, 2012 7:00 AM EST

  • Posted in
  • Storage
  • SSDs
  • Samsung
  • Samsung SSD 840



The DriveRandom & Sequential PerformancePerformance vs. Transfer SizeAnandTech Storage Bench 2011AnandTech Storage Bench 2011 — Light WorkloadPCMark 7, Performance over Time & TRIMPower ConsumptionFinal Words

If we had an award for most improved in the SSD space, it would have to go to Samsung. When we first encountered Samsung MLC drives a few years ago they were pretty bad. Prices were high and performance was low. Samsung offered no end-user upgradable firmware for those early drives either, although that was eventually rectified. The first Samsung MLC SSDs were reliable, they just weren’t worth the money when you had much better options from companies like Intel.

Samsung had all of the right pieces for success however. Like Intel, Samsung made its own NAND, controller and wrote its own firmware. Unlike Intel, Samsung stuck to the vertically integrated formula.

I remember arguing with Samsung engineers a few years ago about the importance of random IO performance compared to sequential speed. I remember feeling like they were making the same mistake that all SSD makers were making back then: heavily prioritizing sequential IO when it was a failure to deliver good random IO performance as well that really hurt SSD adoption. Although the first Samsung SSDs weren’t very good, they got better over time. While the first generation couldn’t be recommended, the Samsung SSD 470 could. It still wasn’t our favorite drive, but it finally brought performance up to a reasonable level. Last year’s 830 release showed us that Samsung woke up. Today, Samsung is adding two new members to the family: the Samsung SSD 840 and the 840 Pro. The former is the first productized consumer SSD to use Samsung’s 21nm 3-bit-per-cell MLC (aka TLC) NAND, while the latter is Samsung’s new flagship drive using 21nm 2bpc MLC NAND.

Unfortunately we don’t have samples of the unique TLC SSD 840, just the MLC 840 Pro. Despite the use of TLC NAND, Samsung claims the vanilla 840 should offer similar performance to the current 830. Samsung also claims that endurance should be reasonable for consumer workloads.

The 840 Pro should be tangibly faster than the 830 thanks to a new controller, new firmware and new NAND:

Samsung SSD 840 Pro vs 830
  Samsung SSD 830 (256,512GB) Samsung SSD 840 Pro (256,512GB)
Sequential Read 520MB/s 540MB/s
Sequential Write 400MB/s 450MB/s
Random Read 80K IOPS 100K IOPS
Random Write 36K IOPS 78K IOPS
Active Power Use 0. 24W 0.068W
Idle Power Use 0.14W 0.042W

While the 830 used Samsung’s 27nm MLC NAND, the 840 Pro uses Samsung’s latest 21nm MLC NAND. The move to 21nm will eventually drive NAND pricing lower, although today Samsung expects price parity between the TLC equipped 840 and the old MLC 830. The 840 Pro should sell for a 25 — 30% premium over the current 830.

Samsung SSD 840 Pro Pricing
  64GB 128GB 256GB 512GB
Samsung SSD 840 Pro $99. 99 $149.99 $269.99 $599.99

The move to 21nm is also coupled with a move to a 400Mbps Toggle 2.0 NAND interface. Block and page sizes remain the same for 2bpc MLC 21nm NAND, and maximum capacity per die is still 8GB. Although beyond the scope of this article, 3bpc TLC 21nm NAND sees 50% slower program/erase times compared to the 2bpc MLC 21nm NAND.

Both the 840 and 840 Pro use Samsung’s 4th generation SSD controller. Samsung’s MAX controller was used in the SSD 470, its successor, the MBX controller, wasn’t used in retail drives, while MCX debuted in the 830 and MDX is in the 840/840 Pro. The basic architecture of the controller hasn’t changed. Internally there are three ARM9 cores now running at 300MHz. Update: Samsung originally listed ARM9 cores but has since told us that there are three ARM Cortex R4s inside of the new MDX controller.

The MDX controller features a hardware AES-256 encryption engine that’s managed using a system BIOS password like most other drives in this class.

The MDX controller is paired with 512MB of LPDDR2-1066 in the Samsung SSD 840 Pro, doubling up the DRAM used in the 830 as well as increasing bandwidth to DRAM by 33%:

SSD DRAM Size Comparison
Drive Controller DRAM Size DRAM Speed
Corsair Neutron GTX LAMD LM87800 256MB DDR2-800
Crucial m4 Marvell 88SS9174 256MB DDR3-667
Intel SSD 320 Intel X25-M G3 64MB SDR-166
Intel SSD 520 SandForce SF-2281 0MB
OCZ Vertex 4 Indilinx Everest 2 512MB/1GB DDR3-800
Samsung SSD 830 Samsung MCX 256MB DDR2-800
Samsung SSD 840 Pro Samsung MDX 512MB LPDDR2-1066

The 840 Pro will be available in 64 — 512GB capacities. Although the controller supports up to 1TB of NAND, Samsung believes that the ultra-high-density NAND required to hit 1TB is too cost prohibitive at this point. Spare area is set at around 7% by default, although users will be able to adjust it via Samsung’s SSD Magician utility. The vanilla 840 on the other hand will boast more spare area (likely to help manage endurance on the TLC NAND) and will launch at 120GB, 250GB and 500GB capacities as a result.

The 256GB SSD 840 Pro features 8 x 32GB NAND devices on the front of the PCB and nothing on the back

The 840 comes with a 3 year warranty compared to a 5 year warranty on the 840 Pro.

The 840 Pro drops the brushed aluminum look of the 830 for slightly more modern, flat black styling. The drives will be available in a 2.5″ 7mm form factor, similar to the 830.

Samsung SSD 840 Pro (top) vs. Samsung SSD 830 (bottom)



Both drives will be available on October 15th, however in advance of the release Samsung provided us with a beta sample for review. We were only able to get a 256GB 840 Pro initially but we’ve already asked Samsung for additional capacities. The other bad news is after running through our client test suite and preparing the drive for a run through our enterprise suite, our pre-production sample died. This isn’t the first time we’ve had an SSD die during our test process, pretty much every company has seen a failure during one of our reviews, but despite Samsung’s excellent track record even it isn’t immune from early issues. These drives are a few weeks away from retail and Samsung will be getting our sample back this week to figure out what went wrong.

Update: My replacement 840 Pro also died, I have shipped both drives back to Samsung and are waiting for their analysis of the failures. 

Update 2: It looks like this may have been a firmware issue. Retail drives should ship with fixed firmware.


Intel Core i7 2600K running at 3. 4GHz (Turbo & EIST Disabled) — for AT SB 2011, AS SSD & ATTO


Intel DH67BL Motherboard


Intel H67

Chipset Drivers:

Intel + Intel RST 10.2

Memory: Corsair Vengeance DDR3-1333 2 x 2GB (7-7-7-20)
Video Card: eVGA GeForce GTX 285
Video Drivers: NVIDIA ForceWare 190. 38 64-bit
Desktop Resolution: 1920 x 1200
OS: Windows 7 x64


Random & Sequential Performance
The DriveRandom & Sequential PerformancePerformance vs. Transfer SizeAnandTech Storage Bench 2011AnandTech Storage Bench 2011 — Light WorkloadPCMark 7, Performance over Time & TRIMPower ConsumptionFinal Words


Samsung 840 Pro SSD review: Samsung 840 Pro SSD

It’s been exactly a year since Samsung released its 830 series solid-state drive (SSD) and today, the company unveiled the upgraded version, the Samsung 840 Pro.

This new drive is actually the professional version of the 840 series, so in a way it’s a double upgrade since the 830 series didn’t have a Pro version. The new drive differentiates itself from the rest of its SSD siblings by using Samsung’s high-performance toggle-mode NAND flash memory, making it the direct competitor to the recently reviewed Corsair Neutron GTX, which uses the same type of flash memory.

In my testing, the new Samsung 840 Pro was very fast, but it wasn’t faster than the 830 series in certain tests, making it hard to justify the new drive’s current cost, which is some 35 percent higher than its predecessor’s. Plus the drive doesn’t come with any accessories such as drive-bay converter for use with a desktop, which makes it much less of a good deal than the 830 series. In the 840 Pro’s defense, it does indeed use much less power than the 830 series, or than other other SSDs I’ve seen for that matter.

That said, if you’re a professional or a hard-core gamer looking for a top-notch SSD for your system, especially if it’s a portable computer, the Samsung 840 Pro will still make a great investment. And it’s not the most expensive SSD on the market, either, costing just between $1. 05 to $1.17 per gigabyte. For others with less demanding needs, I still recommend the Samsung 830 Series.

Design and features

Drive type 7mm-thick, 2.5-inch standard internal drive
Connector options SATA 3 (6Gbps), SATA 2, SATA
Available capacities 64GB, 128GB, 256GB, 512GB
Product dimensions 7mm-thick, 2.5-inch standard
Capacity of test unit 512GB
Controller 3-core MDX controller
Flash memory type 2y-nm class
DDR2 toggle-mode NAND
OSes supported Windows, Mac, Linux

The new Samsung 840 Pro looks almost exactly the same as the Samsung 830 series; the 7mm, 2.5-inch drive looks great and supports the latest SATA 3 (6Gbps) standard. It also works with previous versions of the SATA standard, though.

The new Samsung 840 Pro (top) shares the same design and great-look look as the previous model, the 830 series. Dong Ngo

The new drive comes in a new package that’s much more spartan than the previous model’s. It doesn’t include any accessories, such as a drive-bay converter (which would enable it to fit in the 3.5-inch drive bay of a desktop computer) or a USB-to-SATA adapter. In fact the only thing it does come with is the Samsung Magician (version 4.0) software, which lets you test and change its settings. While this is not a big deal, it does make the new drive that much less affordable than the previous model.

Despite the above similarity in design, on the inside, the Samsung 840 Pro is quite different. It uses a new 3-core MDX controller and toggle-mode NAND flash memory as its storage. This is high-performance flash memory, similar to the kind used in the Corsair Neutron GTX. The combination of the new memory, Samsung’s firmware, and the new controller also means that the new drive uses much less energy than the previous model, which already requires very little power to operate. More specifically, per Samsung’s claim, the new 840 Pro uses 0.068W when in use and only 0.042W when idle, compared with the 830 series, which used 0.24W and 0.14W, in respective states.

Like the 830 series, the new 840 Pro doesn’t come with overprovisioning out of the box. Instead users can use the downloadable Samsung Magician software to turn this feature on or off. Overprovisioning is a feature that enables the use of part of an SSD’s storage space to enhance the drive’s performance. The 840 Pro allows users to reserve between 7 and 24 percent of its storage for overprovisioning, making it one of the most flexible drives on the market when it comes to choosing between speed or maximum capacity. Using the Samsung Magician software, you can also check the SSD’s health status and securely erase its data.

In my trials, the Samsung 840 Pro worked well with all popular operating systems in our trials, including Windows, Linux, and Mac OS X. For better performance it’s recommended that you use the latest version of the OSes that support the TRIM command, such as Windows 7 and Mac OS 10. 6 or later.

Cost per gigabyte
The Samsung 840 Pro costs about 35 percent more than the 830 series. The 256GB capacity, for example, costs $270 compared with $200 for the 830 series. Compared with other SSDs on the market, however, the new 840 Pro isn’t the most expensive, averaging about $1.10 per gigabyte. Note that this is the suggested retail price of the new drive, which, like those of nearly all SSDs, will get lower once the drive has been on the market for a while. Also note that the Samsung 840 Pro comes with a full five-year warranty, which is the longest among SSD warranties.

Cost per gigabyte

Seagate Momentus XT (750GB)


Corsair Neutron (240GB)


Monster Digital Daytona (480GB)


Corsair Neutron GTX (240GB)


Samsung 840 Pro (256GB)


Plextor M5 Pro (256GB)


Monster Digital Daytona (120GB)

$1. 08 

Corsair Neutron (120GB)


Samsung 840 Pro (128GB)


Samsung 840 Pro (512GB)


Corsair Neutron GTX (120GB)


The Samsung 840 Pro performed very well in my testing; it’s among the fastest of all the 7mm SSDs I’ve reviewed. It’s not the fastest, however; in fact, it was slower than its predecessor, the 830 series, in a few tests. As with the 830 series, I tested the new drive with overprovisioning off.

The new drive indeed helped the test machine boot up and shut down very fast, taking just less than 10 seconds and about 5 seconds, respectively. There was no delay when the computer resumed from sleep mode. All applications I tried opened noticeably faster. Since most SSDs help significantly boost overall performance anyway, it’s very hard to quantify the difference between different SSDs, but I could really see the benefit of the Samsung 840 Pro over many other SSDs I’ve reviewed.

Again, most users will not see much difference unless they’re upgrading from a hard drive to an SSD, but if that SSD is the 840 Pro, the improvement will be absolutely great.

The 840 Pro is also designed for those who have already used an SSD. In addition to the performance bump, it also offers better battery life. I tried it with a MacBook Pro in an anecdotal test and the battery life, when using the Samsung 840 Pro, was about 25 minutes longer when compared with when the computer was used with the stock SSD.

In the data copy test, which is generally not the strength of SSDs, the 840 Pro nonetheless did very well at 257MBps when it was used as a secondary drive. When used as the main drive that hosted the operating system and performed both writing and reading at the same time it now scored 168MBps. Both of these numbers were among the top three on the charts but were still slower than those of the 830 series.

Boot and shutdown time (in seconds)
(Shorter bars indicate better performance)

Shutdown    Boot Time   

Samsung 840 Pro

5. 21 


Corsair Neutron GTX



Plextor M5 Pro



Monster Digital Daytona



Corsair Neutron



RunCore Pro V 7mm



Intel 520 series



Seagate Momentus XT (2nd Gen)



WD VelociRaptor 1TB



Data-transfer scores (in MB/s)
(Longer bars indicate better performance)

As secondary drive    As OS drive   

Samsung 840 Pro



Corsair Neutron GTX



RunCore Pro V 7mm


155. 89 

Plextor M5 Pro



Corsair Neutron



WD VelociRaptor 1TB (RAID 0)



Monster Digital Daytona



WD VelociRaptor 1TB



Seagate Momentus XT (2nd Gen)



With very fast performance and very low power consumption, the new Samsung 840 Pro makes a great investment for those who can afford it.

Samsung 840 Pro Series 512GB vs Samsung 860 Pro 4TB 2.5″: What’s the difference?

Type of SSD drive.

SSD cache

02 Unknown. Please help us with a quote. (Samsung 860 Pro 4TB 2.5″)

Solid state drives/SSDs with DRAM flash memory use high-speed RAM as a buffer/cache. Performance is faster than non-DRAM SSDs that use slower NAND flash or system RAM (HMB).

This is an NVMe SSD

✖Samsung 840 Pro Series 512GB

✖Samsung 860 Pro 4TB 2.5″

NVMe SSDs use the PCIe interface, which has a higher bandwidth than the SATA interface. This results in a much higher read speed/

built-in memory


Built-in memory is a built-in space for storing system data, applications and user data in the device. device

SSD storage type

Unknown. Help us offer a price. (Samsung 840 Pro Series 512GB)

Unknown. Help us offer a price. (Samsung 860 Pro 4TB 2.5″)

The storage type determines how many bits of data are written to each memory cell. These storage types include SLC (one bit per cell), MLC (two bits per cell), and TLC (three bits per cell)

PCI Express version (PCIe)

Unknown. Help us offer a price. (Samsung 840 Pro Series 512GB)

Unknown. Help us offer a price. (Samsung 860 Pro 4TB 2.5″)

PCI Express (PCIe) is a high speed expansion card standard that is used to connect a computer to its peripherals. Newer versions support higher bandwidth and provide higher performance.

controller channels

Unknown Please help us with a quote (Samsung 840 Pro Series 512GB)

Unknown. Help us offer a price. (Samsung 860 Pro 4TB 2.5″)

The controller is the processor that controls the functions of the SSD. The number of channels indicates the number of memory chips that this controller can access at the same time. In general, the more channels the SSD controller has, the better the performance

Terabytes Written (TBW)

Unknown Please help us with quote (Samsung 840 Pro Series 512GB)

Unknown. Help us offer a price. (Samsung 860 Pro 4TB 2.5″)

Terabytes written (TBW) is a measure of the life of an SSD and is often covered by the manufacturer’s warranty. Higher TBW can indicate greater reliability over a longer period.


Unknown Help us with a quote (Samsung 840 Pro Series 512GB)

2million hours

MTBF is the manufacturer’s estimate of the average device run time before it fails. 0003

Samsung 840 Evo old data reading problem affects 840 and other solid state drives / Sudo Null IT News Information recorded over a month ago could only be read with a performance drop, and Samsung soon released a patch with a firmware update that was intended to solve this problem. Then it was pointed out that the voltages for cells with old data were not calibrated correctly. As it turned out later, the problem still remained, and the second update should solve it, which periodically overwrites the old data in the background. Per Hansson found out that other Samsung drives with TLC NAND memory are also affected by the degradation problem.

Samsung 840 Evo is drives from 120 gigabytes to 1 «honest» terabyte, available in form factors for connecting via SATA and mSATA. Immediately after the appearance, thanks to the aggressive pricing policy and good performance, they were one of the best solid-state devices for home use. After some time, users began to notice something strange: the data recorded several months ago could no longer be read at full speed. Sometimes the read speed dropped to 30 MB/s. But newly written data was always read at speeds up to 500 MB/s — as fast as any benchmark that writes a new block of information for the test shows. It took only a few weeks for the drop in reading speed to show. By October 2014, the discussion thread on was over a hundred pages long.

This is how the problem appeared six months ago.

Samsung quickly recognized the problem and promised to release a patch. By the end of October, a special utility was released for both 2.5-inch drives (EXT0CB6Q) and drives connected via mSATA (EXT42B6Q). The program performed two simple steps:

  • The disk firmware was updated. The new one took into account the inevitable shift in voltage levels that occurs in all NAND cells as they age. This effect was amplified by the number of bits stored in each cell: only one bit is stored in SLC NAND, and its two states can be easily distinguished. In MLC NAND, each cell stores two bits, and it becomes more difficult to read them, but the amount of data stored is doubled. TLC NAND requires correct calibration of eight voltage levels at once, but the amount of data increases by another one and a half times.

    According to the manufacturer, a bug crept into the algorithm that read the data, causing the old data to become more and more difficult to read. Reading speeds of old files dropped from about 500 MB/s to less than 50 MB/s — 10 times. Detecting this issue was difficult because benchmarks typically write new data and read it immediately to perform a speed test. It is easy for users to notice the problem: operating system files, installed programs and applications, documents are recorded once and used daily.

  • The second step completely overwrote all data on the drive. That is why the execution speed of Performance Restoration Software directly depended on the volume of the drive and the information written to it. Since the speed drop takes about 8 weeks to manifest, it was not clear for a while whether the firmware update worked.

As it turned out later, the first attempt to remedy the situation was not successful. The problem started to reappear. Samsung started working on a new firmware version (EXT0DB6Q), but this time instead of changing the algorithms for reading old data, it was decided to put in the drives periodic overwriting of old files in the background. This solution is not elegant: NAND memory cells wear out from writing and erasing, so the life of the drive will drop. But, as the study of the Tech Report shows, a good resource is laid in modern solid state.

At the time of Hansson’s writing, the update is only available for the 2.5-inch 840 Evo, and mSATA owners need to be patient. Also, the new firmware does not work well with the implementation of the TRIM command in the Linux family of operating systems (the firmware does not support queued TRIM, although the opposite is indicated). An important detail of the latest update is the recognition of the presence of a flaw not in the firmware of the drives, but in Samsung’s TLC NAND chips. Probably, the manufacturer cannot write such an algorithm that could take into account the aging of information in the cells, so it is proposed to overwrite them.

Samsung claims that the problem is only with the 840 Evo. But it’s not. There are other versions for embedding, for example, Samsung PM851, which falls into Dell products. On the forums, users report the same problems with reading speed. Embedded versions of Samsung drives can also be found in the Razer Blade Pro laptop and Microsoft Surface Pro 3. In the latter case, Samsung released a firmware update, but later removed it from the site without explanation.

Also potentially affected is the Samsung 845DC Evo, an enterprise version of the drive, as stated on the site, specifically built for «read-intensive applications.» 845DC Evo uses the same TLC NAND chips as 840 Evo — K90KGY8S7M-CCK0. It is likely that Samsung chooses the best components for industrial solid state drives, so it may take time for reading speed drops to show up and for heated forum discussions to start.

Finally, there’s the 840 (no Evo in the name), which was the first to use TLC NAND. At the moment, a firmware update for this drive has not been released. Although the drop in reading speed is also evident here, Samsung does not acknowledge the problem. Samsung Germany previously stated that older data on the 840 is slower to read, but this was later refuted in company reports. Here is Samsung’s answer to a question from PC Per.

PC Per: Will there be a firmware update for other Samsung TLC SSDs that have also exhibited this read speed issue? If so, when and for which models will new firmware versions be released?
Samsung: This issue has only been reported for 840 Evo SSDs.

Hansson cites the data he gathered from user posts on the forums:

  • 840 Evo uses TLC NAND with process 19nm, and degradation takes 8 weeks.
  • Regular 840 is based on 21nm TLC NAND, needs 40 weeks to age.

Below is the drop in read speed on the 840 model. The test was performed by Hansson on a Lenovo ThinkPad T530 laptop running Windows 7. A Plextor M5M mSATA was used as the primary drive, a Samsung 840 as the secondary drive. HD Tune was set to a block size of 64 KB. An empty 40 GB is not subject to read speed degradation, so it achieves a peak performance of 375 MB / s. You can see that the first part experiences a particularly severe read speed drop — this happened due to the cloning of a regular hard drive on a Compaq laptop, and the first 13 GB contains a recovery partition. In these 13 GB, which were never overwritten, there is a noticeable peak of two empty gigabytes.

Faced with the problem of reading the 840 Evo, forum user Techie007 created a very useful SSD Read Speed ​​Tester utility that can graph the read performance of individual files depending on their age. Hansson also checked his 840, and concluded that the reading problem was confirmed.

The visualization of the result is limited to 99 weeks, and there was older data on the disk. Hansson built a graph in Excel using raw data, days are plotted on the abscissa. When analyzing the results of the data, it becomes clear that the older the file, the worse it is read.

For comparison, this is the result of the Samsung 840 Pro, which uses MLC NAND memory cells that store two bits and require calibration of only four voltage levels. There is no drop in reading speed on it.

Another interesting observation was the dependence of performance on temperature. The benchmark results «floated», and Hansson found that this was due to the temperature of the drive. The warmer 840, the better old data is read. But this may not be true for all types of solids — they can be calibrated to a different temperature. It is also impossible to increase the temperature above the threshold: in case of overheating, the controller will limit the data transfer rate. These phenomena once again emphasize how difficult it is to correct the reading algorithm.

At 15°C, the speed is noticeably slower than at 40°C.