CNET logo Why You Can Trust CNET

Our expert, award-winning staff selects the products we cover and rigorously researches and tests our top picks. If you buy through our links, we may get a commission. Reviews ethics statement

Samsung 840 Pro SSD review: Samsung 840 Pro SSD

Samsung's 840 Pro SSD uses less power than comparable drives but doesn't skimp on performance.

Dong Ngo SF Labs Manager, Editor / Reviews
CNET editor Dong Ngo has been involved with technology since 2000, starting with testing gadgets and writing code for CNET Labs' benchmarks. He now manages CNET San Francisco Labs, reviews 3D printers, networking/storage devices, and also writes about other topics from online security to new gadgets and how technology impacts the life of people around the world.
Dong Ngo
6 min read

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.


Samsung 840 Pro SSD

The Good

The <b>Samsung 840 Pro</b> offers fast performance and uses significantly less energy than other solid-state drives.

The Bad

The Samsung 840 Pro is comparatively expensive.

The Bottom Line

The Samsung 840 Pro lives up to its name: it's a top-notch solid-state drive for professionals with a price to match.

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.
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.

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)
Boot Time  
Samsung 840 Pro
Plextor M5 Pro
Corsair Neutron
OCZ Vertex 4
OCZ Octane
Intel 520 series
Patriot Pyro
SanDisk Ultra
WD VelociRaptor 300GB

Data-transfer scores (in MB/s)
(Longer bars indicate better performance)
As secondary drive  
As OS drive  
Samsung 830 Series
OCZ Vertex 4
Samsung 840 Pro
Corsair Neutron GTX
RunCore Pro V 7mm
Plextor M5 Pro
Intel 520 series
Corsair Neutron
Monster Digital Le Mans
Sandisk Extreme
Monster Digital Daytona
OCZ Agility 3
RunCore Pro V Max
Sandisk Ultra
WD VelociRaptor 1TB
WD VelociRaptor 600GB
Seagate Barracuda XT
WD VelociRaptor 300GB

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 SSD

Score Breakdown

Setup 8Features 8Performance 8Support 8