Samsung 840 Series TLC 250GB SSD Review

Samsung leads the way by introducing the world's first SSD equipped with TLC NAND into the market. The Samsung 250GB 840 Series SSD looks to shake up the market by providing an excellent dollar-to-performance ratio by leveraging low cost NAND and the high-powered MDX controller. Does its performance equal the value expectation?



The TLC NAND onboard the Samsung 840 Series brings us more questions than we have answers at this point. With the new TLC NAND being very much untested in real user environments it is going to be hard for us to draw straight lines in comparison to expected long term behavior of these SSDs. There are concerns that we will cover in a moment, but first let's talk about what Samsung got right.

One area that Samsung has excelled is in the ease-of-use category. This is important, most users do not want to spend a large amount of time managing and maintaining their SSD. Many of the SSDs that we review have excellent performance and pricing, yet lack the tools that make owning an SSD easy and enjoyable. One aspect of the utility that is particularly helpful is the ability for users to easily adjust the over-provisioning level of the SSD. Extra over-provisioning helps to level out long term performance and brings the huge benefit of increased endurance that is especially pertinent with the type of NAND employed on the Samsung 840.

The SSD Magician software from Samsung takes the 'hard work' out of owning an SSD. Something as simple as the auto-download feature for the firmware can save users a significant amount of time, even before the time saved by not needing to create bootable media is factored in. We would love to see other companies follow Samsung's led in this area, since the only other company with a comparable utility is Intel at the moment.

The Samsung 840 did exhibit some surprisingly good base latency numbers in average read and write categories, and equally good maximum latency measurements. The random write latency is especially good for the type of NAND employed, which can mitigate performance issues with operating systems and applications due to the low write speeds across the board. There are concerns that come to mind about the latency of the SSD when it comes to long-term performance, as we did note some significant read speed degradation in our steady state testing.

The Samsung 840 did perform well in our PCMark Vantage testing in steady state, managing to best many of the competing SSDs. It did not score as well in the PCMark 7 testing, where it suffered from its slower write speeds.

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The low write speed offered with the Samsung 840 Series is going to be a concern for some users. It is especially important that users with moderate to heavy write workloads carefully weigh other options before making the jump to a TLC SSD. The low write speed will be an immediate problem in large file transfer situations, and endurance will be a long-term problem. It is also important to note that the 120GB model of this SSD only has a sequential write speed of 130MB/s and random read IOPS of 32,000, significantly lower than the lackluster write performance that we observed today in our testing.

Including a thermal pad for the controller would help to keep the device cool. We would like to see thermal pads with this SSD when we take the higher power consumption figures from TLC NAND into consideration.

There are concerns that will only be answered with the test of time. There are some absolutes that we do know exist with this type of NAND, and we can use these to theorize about some aspects of long term performance in relation to several factors of the SSD.

Our steady state testing essentially places a workload upon the SSD until it is forced to begin running the internal management routines and garbage collection during actual usage. This is especially important with this type of NAND as it is definitely going to experience far more data errors than MLC over time. This will create increasing overhead for the MDX controller over the lifetime of the device. The read speed degradation that we observed is worrisome due to the fact that the increasing error rates can trigger these drive management routines, in effect creating read speed degradation in lower usage scenarios than with MLC NAND.

The extreme loss of write performance in steady state in our Iometer testing can also be a sign of long term performance issues in steady state as the NAND ages. We do not have comparable TLC SSDs to test yet, so making quantitative comparisons to other TLC products is, at this point, impossible.

The higher power figures would not make this our first recommendation for mobile devices, especially when taking into consideration the increased power consumption that will be inevitable as the SSD ages and the errors begin to proliferate.

We are disappointed that Samsung chose to only provide a three year warranty for all capacities of this SSD, though it is understandable with the 120GB model. Many companies are now giving five year warranties, and we feel that the endurance of the 250 and 500GB models calls for a five-year warranty. This would do wonders to soothe users who are worried about endurance with the new TLC NAND.

At the time of publishing the 120GB Samsung 840 is $96.13, the 128GB Samsung Samsung 840 Pro is $144.77, the 128GB OCZ Vector SSD is available for $149.99, the 120GB Corsair Neutron GTX for $129.98, and the 120GB Kingston HyperX 3K retails for $112.05.

The 250GB Samsung 840 is $175.99, the 256GB Samsung 840 Pro is $269.99, the 256GB OCZ Vector is retailing for $269.99, the 240GB Corsair Neutron GTX for $229.99, and the 240GB Kingston HyperX 3K for $184.43.

The 500GB Samsung 840 is an astounding $346.77, the 512GB Samsung 840 Pro is $570.65, the 512GB OCZ Vector retails for $569.99, the 480GB Corsair Neutron GTX for $469.99, and the 480GB Kingston HyperX 3K for $529.99.

SSD retail prices can fluctuate wildly, so it is always good to check around and see what others are finding to be a deal.

The Bottom Line

The Samsung 840 Series requires users to know their workload before making the jump. This SSD should be fine for the casual user, but for those with heavy write workloads there will be penalties in overall speed and endurance. Samsung is looking to shake up the value segment with the inclusion of TLC NAND units. Look for more TLC SSDs to come into the market, but currently Samsung has the only working silicon in this aspect on the market. The Samsung 840 Series enjoys a considerable price advantage in relation to enthusiast-class SSDs. Particularly in the higher capacity segment the price of the Samsung 840 will reign supreme for the time being. For those looking for cost savings in a high capacity performance SSD, the scaling penalties of the write speed and endurance could be somewhat overlooked, providing a compelling reason to make the jump to TLC NAND and the Samsung 840.

Saving $100 dollars in the 250GB, and $200 in the 500GB categories is going to persuade many users to make the jump regardless of the lower write speeds. From a value perspective there is no better value, especially for those looking for large capacity SSD that exhibits overall good performance. If you are moving from a spinning SSD and size is important to you, the value is very attractive.

We give the [H]ardOCP Silver award for the continued innovation that Samsung has displayed with the 840 Series of SSDs, and we look forward to other manufacturers deploying TLC solutions so we can continue to enjoy price drops in the overall SSD market. Certainly though, Samsung has set a benchmark for others to compete with in the TLC SSD market. While it may be a stretch to call the Samsung 840 an "enthusiast class" SSD, it is certainly a solid product choice for those looking to make the jump into the Solid State Drive arena. While we have not tested the 120GB Samsung 840, we have reservations about lumping the 120GB capacity Samsung 840 into our award category, simply due to technical limitations imposed upon it.

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Samsung 840 SSD آ– 250GB آ– 500GB