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Samsung 840 Evo review: Finally, an SSD that has almost everything

The Samsung 840 Evo offers great performance, top capacity, and a helpful software bundle, and doesn't dig a hole in your wallet. What else can you ask for in a solid-state drive?

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
7 min read

There are three important things you should keep in mind when buying a solid-state drive: capacity, performance, and pricing. And the new Samsung 840 Evo makes things easy by offering them all, and more.


Samsung 840 Evo

The Good

The <b>Samsung 840 Evo</b> solid-state drive offers overall excellent performance, top storage space, and useful bundled software, at low cost.

The Bad

The three-year warranty is relatively short, and the drive's sequential read speed could be a tad better.

The Bottom Line

If you're looking for a fast SSD that offers top capacity at low cost, look no further than the Samsung 840 Evo.

The new drive is a replacement for Samsung's previous entry-level 840 Series drive, but the only thing entry-level about it is the pricing. Its performance is among the best I've seen, and the drive is also the first consumer-grade SSD to hit the 1TB mark in storage space. In addition, the 840 Evo is bundled with valuable software that further boosts its performance.

At the current price of well under $1 per gigabyte -- the 1TB capacity costs just $650, or about 65 cents per gigabyte -- the Samsung 840 Evo is the best deal on the market now, ranking at the top of the current best SSD list. If you're looking for an SSD to upgrade your computer's hard drive with or want to upgrade your existing SSD to a larger-capacity drive, the 840 Evo is as good as it gets.

The new Samsung 840 Evo shares the same design and standard as previous generations, but now comes in gray.
The new Samsung 840 Evo shares the same design and standard as previous generations, but now comes in gray. Dong Ngo/CNET

The Samsung 840 Evo looks the same as the older 840 Series, but now comes in dark gray. The drive supports the popular 7-millimeter, 2.5-inch design and features the latest SATA 3 (6Gbps) standard. It also works with previous versions of the SATA standard.

Drive type 7mm-thick, 2.5-inch standard internal drive
Connector type SATA 6Gbps (compatible with SATA 3Gbps and SATA 1.5Gbps)
Capacities 120GB, 250GB, 500GB, 750GB, and 1TB
Review capacity 750GB
Controller Samsung MEX controller
NAND flash memory 1x nm Samsung Toggle DDR 2.0
Sequential read: Up to 540MBps
Sequential write: Up to 520MBps (250GB/500GB/750GB/1TB), and up to 410MBps (120GB)
4KB Random read (QD1): Up to 10,000 IOPS
4KB Random write (QD1): Up to 33,000 IOPS
4KB Random read (QD32): Up to 98,000 IOPS (500GB/750GB/1TB); up to 97,000 IOPS; (250GB); up to 94,000 IOPS (120GB)
4KB Random write (QD32): Up to 90,000 IOPS (500GB/750GB/1TB); up to 66,000 IOPS (250GB); up to 35,000 IOPS (120GB)
Encryption AES 256-bit Full Disk Encryption (FDE)
Weight 1.9 ounces
Reliability MTBF: 1.5 million hours
Warranty 3 years limited

The drive is available in five capacities, 120GB, 250GB, 500GB, 750GB, and 1TB, all of which come with the Samsung Data Migration Tool and Samsung Magician Software included. The former is an advanced cloning program that helps you move data from one drive to another without having to reinstall the operating system or software; and the latter is a set of powerful tools for customizing the drive.

The Desktop Kit includes all you need to upgrade your your computer's existing drive to a new 840 Evo.
The Desktop Kit includes all you need to upgrade your computer's existing drive to a new 840 Evo. Dong Ngo/CNET

To help make life even easier for upgraders, the drive is also available in a Desktop Kit version for the 120GB and 250GB capacities, and a Laptop Kit version for the 250GB and 500GB capacities, respectively costing $15 more and $10 more than if you buy just the SSD itself. The Desktop Kit includes a drive bay converter caddy, a 2.5mm spacer to bring the thickness of the drive to the 9.5mm standard, a CD of software, and a USB 3.0-to-SATA adapter. The Laptop Kit consists of just the software, the spacer, and the USB 3.0-to-SATA adapter.

With either of these kits, folks can quickly clone their computer's existing hard drive to an 840 Evo, without having to get extra equipment. The software CD contains the above-mentioned Samsung Data Migration Tool and Samsung Magician Software, which can also be downloaded from Samsung's Web site.

Useful software, flexible configuration
Like previous Samsung SSDs, the 840 Evo doesn't come with overprovisioning out of the box. Instead you can turn this feature on and off using the Samsung Magician Software. Overprovisioning is a feature that uses part of an SSD's storage space to enhance the drive's performance. Thanks to this, the 840 Evo offers the flexibility to choose between maximum speed or capacity.

Using the Samsung Magician Software, you can also check the SSD's health status and securely erase its data, or tune up the operating system settings to maximize the drive's speed and endurance.

The new Samsung Magician Software comprises a lot of useful tools and makes the 840 Evo the most flexible SSD on the market.
The new Samsung Magician Software comprises a lot of useful tools and makes the 840 Evo the most flexible SSD on the market. Screenshot by Dong Ngo/CNET

Modern and performance-oriented software and hardware features
There are a couple of things that help make the 840 Evo so fast.

Firstly, Samsung Magician now offers a new function, introduced in the 840 Evo, called Rapid mode, which can be turned on or off with a click. When on, Rapid automatically uses part of the host computer's system memory (RAM) as cache to further boost the drive's performance. Depending on the available RAM, Rapid uses between 500MB and 2GB for this purpose. In my test, Rapid indeed significantly improved the drive's performance.

Secondly, in the area of hardware, the new drive uses a new and improved Samsung MEX controller, which is based on the three-core MDX controller used in the 840 Pro, and its fast Toggle DDR 2.0 NAND flash memory. The drive also has improved firmware to deliver significantly faster performance than the 840 Series.

And finally, the 840 Evo supports a feature called TurboWrite Technology, which, depending on the capacities involved, offers double or triple the sequential write performance of the 840 Series. With Turbo Write, part of the solid-state drive is made of single-layer cell (SLC) NAND flash memory, the type of NAND used mostly in high-end enterprise SSDs. This part is used as a buffer for writing. Basically, data gets written on the buffer first and will then be moved to other parts of the SSD when the drive becomes idle. Since in real-world usage an SSD is idle most of the time, Turbo Write works very effectively.

And speaking of idle, the 840 Evo uses very little power when not in use, just 0.045 watt, compared with the 0.5 watt of a regular hard drive or certain SSDs. (The 840 Series uses 0.046 watt.) This makes the new drive a great fit for laptop users.

In my trials, the Samsung 840 Evo worked well with 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. Note, however, that the drive's bundled software only works with Windows.

Rapid mode uses part of the system's memory (RAM) to further boost the 840 Evo's performance.
Rapid mode uses part of the system's memory (RAM) to further boost the 840 Evo's performance. Screenshot by Dong Ngo/CNET

Cost per gigabyte and warranty
Pricing is always the biggest concern when it comes to SSDs, but the 840 Evo delivers. The drive's five capacities of 120GB, 250GB, 500GB, 750GB, and 1TB cost $110, $190, $370, $530, and $650, respectively. Except for the 120GB capacity, which costs about 92 cents per gigabyte, these are all less than 80 cents per gigabyte. And again, the 1TB capacity is even less per gigabyte, at just 65 cents.

It's fair to say that the 840 Evo brings SSD pricing lower than ever. It's likely its price will get even lower the longer the drive is on the market.

It's worth noting that the 840 Evo comes with only a three-year warranty, not the five-year of the 840 Pro and some other high-end drives. But three years is rather standard for a drive that's categorized as entry-level.

Cost per gigabyte (in dollars, based on street pricing at time of review)
(Shorter bars indicate better performance)
Samsung 840 Evo (1TB)
Samsung 840 Evo (750GB)
Samsung 840 Evo (500GB)
Samsung 840 Evo (250GB)
Samsung 840 Evo (120GB)

I actually compared the 840 Evo against other high-end SSDs and it was impressive. The test computer took just about 10 seconds to boot up and about half of that to shut down. The drive also helped the machine resume from sleep-mode almost instantly. Applications, including heavy ones, such as games, also took much less time to load than when the computer was running on a hard drive.

The Evo offered much faster write speed than read speed, scoring 267MBps for writing and 184MBps for reading, in a straightforward data-copying test. When working as a main storage drive hosting the operating system and performing both writing and reading small files at the same time, the drive managed 257MBps. All of these speeds were really fast compared with the other drives' performance.

Yet the drive was even faster with Rapid turned on, scoring 289MBps for writing, 193MBps for reading, and an impressive 378MBps combined, the best I've seen

With PCMark 8, the 840 Evo scored 4,967 Storage points, and 4,990 points with Rapid turned on. Its reading score was lower than other high-end drives', but the 840 Evo was among the fastest in the other categories.

Internal hard drive data transfer (in MBps)
(Longer bars indicate better performance)
As secondary drive (read only)
As secondary drive (write only)
As OS drive (read and write)
Samsung 840 Evo (Rapid)
Samsung 840 Evo
OCZ Vector
Plextor M5 Pro Xtreme
SanDisk Extreme II
Seagate 600 SSD
Transcend SSD720
Seagate Laptop Thin SSHD

PCMark 8 scores
(Longer bars indicate better performance)
Samsung 840 Evo (Rapid)
Samsung 840 Evo
OCZ Vector
Plextor M5 Pro Xtreme
SanDisk Extreme II
Seagate 600 SSD
Transcend SSD720
Seagate Laptop Thin SSHD

The new SSD also increased the battery life of a computer by about 25 minutes compared with a regular 7,200rpm laptop hard drive, in my anecdotal testing.

With fast overall performance, affordable prices, and a top storage capacity of 1TB, the Samsung 840 Evo has almost everything you'd look for in an internal storage device. What could be improved, namely the slightly slow sequential read speed and the relatively short three-year warranty, are just a minor shortcomings that don't change the fact that the drive is the best deal on the market now. The new drive opens up a new and exciting chapter in which solid-state drives are comparable to regular hard drives in terms of capacity and even pricing, while remaining so much faster in performance.


Samsung 840 Evo

Score Breakdown

Setup 8Features 9Performance 9Support 8