Quick Review: Samsung 850 Pro 1TB (MZ-7KE1T0) Solid State Drive

One night, staying up late after doing some work, I caught the fact that eBay was having a 15% off “everything” sale. A few minutes later, a bright idea popped in my head, and almost equally as quickly, over AU$500 had been spent. The bright side? Well, I did manage to take full advantage of the AU$100 maximum discount on offer.

I know it’s a bit late, but I’ve finally gotten my hands on the venerable Samsung 850 Pro – the successor to an already voracious 840 Pro, which provides further refinements and a change of technology from planar NAND to 3D VNAND. This MLC based offering has higher levels of endurance, with about 6000 cycles expected, and none of the performance and endurance disadvantages from TLC offerings. It really is a great SSD for a power user, especially at a capacity of 1Tb (with 2Tb already announced, and 4Tb on the way using the same 850 Pro branding).

The Pro series has always commanded a premium, and generally costs north of AU$0.63/Gb. The Evo series is intended for mainstream users, with TLC memory, and tends to sit at the AU$0.45-0.50/Gb price point. When I saw the effective price I was paying was AU$0.56/Gb, it felt like a bargain.

But there’s a twist. It’s not for me. Instead, I’ve bought it on behalf of someone else, and in the process, I’ve put it through a quick per-commissioning test just to be sure it’s good. I’m sure they won’t mind.


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From the outside, the box for the 850 Pro is reminiscent of the one the 840 Pro shipped in. Both are about a 1.5x thick CD jewel case in size, with mostly black printing and a matte lustre finish. Instead of orange, the Pro series takes on a red colouration. A special distinguishing feature is the 10 year limited warranty, with a manufacturer guarantee of 150TBW (terabytes written). This is just a slight bit more than twice the 72TBW formerly touted by some manufacturers, although it’s a figure that even a TLC-based 1Tb SSD should easily sail past. Most endurance tests to date have seen superlative performance, with SSDs sailing past the guaranteed lifetime by several fold, although retention of the data may have been degraded. The Samsung 840 Pro was quite notable for its endurance, with a 256Gb sample reaching 2400TBW prior to death and the 850 Pro should improve on this.


As with all the Samsung retail SSDs, you really don’t get many inclusions that you want or need, and quite a few things that you really don’t. For example, there is no SATA cable, Molex adapter, or 9.5mm/3.5″ conversion brackets. Instead you get two lousy labels to advertise their brand, two printed leaflets, a warranty card and the Magician software on a CD. I mean, who even has a optical drive nowadays? [Sheepishly pretends that I don’t.]

But seriously. Download it from their website. Don’t bother with the disc. That’s the only way you’ll ever get the latest firmware.


The drive itself is somewhat simple and elegant in its appearance. Matte black with a chromed beveled edge seems to be the order, although it is still light and somewhat tinny in its construction. It seems effort was put in, and it carries over from the 840 Pro which featured an orange square instead of the red square.


The underside features a label identifying the model, serial numbers, etc.


Because of timing requirements, testing of this SSD was not completed on my regular test machine. Instead, a newer machine that was not in active use was commissioned to do the testing. The machine was based around an overclocked Pentium G3258 with 8Gb Samsung RAM on a Asrock Z97-M Pro4 motherboard running Windows 7 (with latest updates) and MS AHCI drivers (due to iRST instability). The chipset would offer performance commensurate with the current generation of machines, however, the slower CPU could prove to be a bottleneck in some of the benchmarks – so keep that in mind. This is sort of the opposite of testing with my older AMD based platform.

As this new test platform was recently cobbled together, the versions of benchmarking software are also different which can have an impact on the results. Regardless, it’s probably not so exciting for everyone since the 850 Pro is “old news”, but it does serve as a record of the performance I experienced during commissioning the hardware.

Samsung Magician 4.2

The first step was to see if this was the real deal – and indeed, according to Samsung Magician, it was. It was also running the latest firmware, thus does not need any upgrading.



As with Samsung SSDs, the SMART parameters are not too numerous but are relatively well documented. You can see that at the end of all testing, approximately three-and-a-bit cycles were consumed.

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HDTune Pro


As with prior Pro-series drives, this drive manages to turn out impressive figures. Average read rate across the surface was 527.3MB/s. It’s important to note that variations from say, 500MB/s to 550MB/s are meaningless, and probably arise from individual variations due to the chipset and device timings.


The write speed achieved was a perfectly round 500MB/s, which is really pushing SATA III to its limits. On the whole, the figures are slightly less than the advertising figures, which may be due to different test conditions or more “matched” port controllers, but it’s amazing to see this level of performance on a sustained basis.

850pro-hdt-raread 850pro-hdt-rawrite

For completeness, a random access/IOPS test was also performed, both read-and-write. I’m not particularly a fan of these tests as the numbers can be quite wildly fluctuating, and never quite meet the advertised figures (due to differences in testing, latency of the test routine). Regardless, it seems the drive is turning out fairly impressive write IOPS, especially at 4Kb. I suspect the test is QD1, so queuing is not being taken advantage of, explaining the comparatively lower read-IOPS figures, which are still quite impressive in themselves.


This is also borne out in the file benchmarks, where a high queue depth of 32 improves the read IOPS dramatically. On the whole, with transfers above about 128Kb, the full speed is reached. The 32-depth IOPS seems a bit on the low side, and I suspect that may be due to the CPU being hammered trying to take care of all the transactions in the air.



Another standard benchmark, which mostly reflects what we’ve already seen, but it seems that the sequential figures are more favourable under this benchmark, now much closer to the manufacturers’ claims. The same pattern with low-queue-depth results is seen, but is still quite a bit ahead of some of the other SSDs I have used in the past – for example, the Sandisk Extreme II 480Gb, another performance-level SSD, scored 33.31MB/s 4K Read and 84.78MB/s 4K Write with QD32 results of 279.5MB/s and 239.0MB/s respectively on the old test platform.



An old, simple benchmark which many manufacturers game, I mean, use as their official metric. Interestingly, ATTO performance seems to show most of the read and write performance has been attained at 16kB – 32kB transfers, with a very impressive result for 512 byte transfers (compared to what I normally see). This is a different result to what HDTune seems to suggest. The speeds reported by ATTO are also right on the dot with the manufacturers – e.g. 563151Kb/s read = 549.95MB/s, and 533315Kb/s write = 520.82MB/s.

AS-SSD Benchmark


It seems AS SSD is having some trouble with this drive. It’s reporting an anomalously high score, with a 4K 64-thread result of 1152.02MB/s which is physically impossible. During testing, the benchmark can be seen to freeze during this test and then suddenly come back to life, so I think it’s safe to say that it’s more likely that the high score was due to the CPU not being able to keep up. So please, disregard the figure – most SATA III drives don’t score above ~860 or thereabouts, and scores above ~1200 really aren’t plausible.


As is tradition for being thorough, the drive itself does not appear to have any compression-related performance discrepancies.


Surprisingly, the copy-benchmark has this drive lagging very slightly behind the result of the Sandisk Extreme II (2.43s, 4.80s, 3.81s) although due to the difference in test platform, this could be again CPU related.

Anvil Storage Utilities


Anvil seems to be a fairly popular bench, so it was also tested. The drive did perform quite well, registering a score of 5301.27, with the 840 Pro on the old test platform registering 4150, and the Sandisk Extreme II registering 3860. This is by far the best result I have so far.



It’s more a test of the data integrity than a benchmark, but H2testw was used to ensure the drive stores and retrieves data without corruption. A single pass was completed with no errors and a transfer rate close to 400MB/s each way, likely limited by the CPU.


As expected, Samsung’s 850 Pro is a monster of an SSD. It turns out great performance figures for a client SSD and is starting to be limited by the ability of the SATA III connection. The 3D VNAND technology remains a specialty of Samsung (although Toshiba’s BiCS technology will also compete soon as a price reduction measure). This means that even their TLC based Evos stand to benefit dramatically from the increased endurance. Impressively, they have improved on the figures I saw previously from the 840 Pro which I considered to be a “pinnacle” of SATA SSDs. Of course, the future is PCIe and NVMe based storage with multi-GB/s speeds, but for older machines and mainstream users today, SATA III will remain relevant for at least a few more years.

I suppose none of this comes as a surprise, given how many people do champion Samsung 850 SSDs in general, including myself, however what is surprising is how many seem to opt for the Evo over the Pro to save some money. I think the Pro itself can be worth the small premium, especially if you do lots of unusual power-user style workloads that involve lots of writes. After all, some of my MLC drives have chalked up over 300 cycles (i.e. the amount TLC drives are generally warranted for).

In the end, I won’t be keeping this drive – it will be going to a good home. Instead, my older Sandforce 120Gb drives will probably keep me going for at least a few more years …

About lui_gough

I'm a bit of a nut for electronics, computing, photography, radio, satellite and other technical hobbies. Click for more about me!
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