Why You Can Trust CNET Samsung 840 series review: High-end entry-level SSDs
The Samsung 840 series is a great entry-level solid-state drive thanks to its decent performance and very friendly pricing.
The Samsung 840 series, which is not to be confused with the recently reviewed
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The Good
The Bad
The Bottom Line
That said, it's probably the best entry-level SSD you can find out on the market. This is because the Samsung 840 is not just great-looking but also offers the kind of performance that you'd expect from a more expensive drive. It's an excellent choice for budget home users who want to move up from hard drives for their laptops.
Professionals or those wanting top speed or durability, however, should still stick with the good-old Samsung 830 series, or the new 840 Pro, or any other drives on this top-five list.
Design and features
| Drive type | 7mm-thick, 2.5-inch standard internal drive |
| Connector options | SATA 3 (6Gbps), SATA 2, SATA |
| Available capacities | 120GB, 250GB, 500GB |
| Product dimensions | 7mm-thick, 2.5-inch standard |
| Capacity of test unit | 250GB |
| Flash memory type | 3-bit-per-cell MLC NAND or TLC NAND |
| OSes supported | Windows, Mac, Linux |
The Samsung 840 looks exactly the same as the Samsung 840 Pro. Unless you check the bottoms of the drives, you could easily mistake one for the other. Upon inspection, you'll find that the new 840 series drive comes without the Pro designation and in three capacities of 120GB, 250GB, and 500GB, whereas the the 840 Pro is available in 64GB, 128GB, 256GB, and 512GB capacities.
The new, non-Pro 840 series, however, also comes in the ultrathin (7mm) design and supports SATA 3 (6Gbps).
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On the inside, the Samsung 840 series is very different from both the 830 series and the 840 Pro. The 840 series drive uses the new 3-bit-per-cell MLC NAND (also known as triple-level-cell or TLC NAND). In fact, it's the first mass-production consumer SSD that uses this type of flash memory.
TLC NAND is generally slower and cheaper than regular MLC NAND -- which is the mainstream flash memory for consumer-grade SSDs -- and has been more often used for other forms of flash-based storage devices, such as thumbdrives or memory sticks. Technical jargon aside, with the 840 series, Samsung's aim is to bring down the cost of SSDs. The question is, at what level of performance sacrifice? You can find the answer in the performance section below.
A shortcoming of the 840 series is that TLC flash memory generally has lower write endurance than other type of SSD NAND. Write endurance, also known as the program/erase (P/E) cycle, is an attribute that dictates how many times you can write and rewrite information on a memory cell before it won't retain the new information anymore. Because of that, the 840 series will likely become unreliable sooner than other SSDs. This might be why the Samsung 840 series comes with a three-year warranty, compared with the five-year warranty offered with the 840 Pro and the 830 series. The new drive also doesn't comes with capacities smaller than 120GB, since generally with SSDs, smaller capacities also means less P/E cycles.
In real-world usage, this lower write endurance is not really a big issue, however. Per my rough calculations, if you write/rewrite about 10GB of data daily, it would still takes about 7 years for a 250GB Samsung 840 series drive to run out of P/E cycles. Most of us don't write 10GB per day, at least not every day. But heavy users, such as video-editing professionals, should pick a different SSD for their job.
The 840 series comes in two retail packages: with and without the installation kit. The latter costs about $30 more than the former. The installation kit package includes accessories for first-time SSD buyers who want to have everything they need to clone their existing systems from a hard drive to the new SSD. The bare-bones version includes just the SSD and a CD that contains manual and the Samsung Magician 3.2 software.
The software offers a few handy tools for users to manage, test and customize their 840 series drive. One of these tools is the ability to toggle overprovisioning. The 840 series drive doesn't come with overprovisioning out of the box, leaving the users the options to manage this themselves. Overprovisioning is a feature that enables the use of part of an SSD's storage space to enhance the drive's performance. With the the 840 series, you can 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.
In my trials, the Samsung 840 series worked well with all popular operating systems, 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 biggest selling point of the Samsung 840 series is, well, is pricing. This is the first drive from Samsung, and arguably the first on the market for that matter, that costs well less than $1 per gigabyte at launch. Right now you can get a 250GB bare-bones version of the drive for just $180, making it one of the most affordable SSDs on the market. The price is expected to get even lower soon, just in time for the holiday shopping season. The Samsung 840 series might be the beginning of an era where SSDs' performance more than justifies their cost.
Performance
Because the new Samsung 840 series uses TCL flash memory, I didn't expect much from it, but I was wrong. It seems that Samsung has done a good job with the controllers, which enables the new drive to offer performance on par with many other SSDs on the market. The drive, as expected, wasn't the fastest I've seen, but it managed to be fast in some tests. And yes, it was also comparatively slow in other tests.
When used as a secondary drive, the Samsung 840 series had a data writing speed of about 231MBps, right about the average on the chart. This is very good since it's at the top theaffordability chart. When used as the main drive that hosts the operating system, and performed both read and write at the same time, the drive reached a speed of just 103MBps. Note that being the main drive is the most popular use for SSDs.
When used as the main drive, the 840 series helped speed the boot time of the test machine a great deal at just 11 seconds (compared with about a minute when a standard hard drive is used). The shutdown time was also cut down to just about 6 seconds (from around 12 seconds with a hard drive.) These scores were actually on par with those of most SSDs I've reviewed.
The computer's overall performance was also greatly improved when compared with using hard drives. Everything was much faster and most applications loaded instantly. Heavy apps, such as games, also took much less time to get ready. Overall, most novice users won't notice the difference between the Samsung 840 series and other higher-end, more expensive drives.
While I didn't test the drive's power consumption, it appared to use less power than the 830 series and slightly more than the 840 Pro. If you have experiences with all three drives, you'll notice the difference in your laptop's battery life accordingly.
In all, the Samsung 840 series proved to be an excellent entry-level SSD in terms of performance.
(Shorter bars indicate better performance)
 | Shutdown | | Bootup |
(Longer bars indicate better performance)
| As Secondary Drive | | As OS Drive |
Conclusion
Affordable, good looking, and offering decent performance, the Samsung 840 series is an excellent SDD for home users on a budget.