XSReviews

I recently bought a Samsung 840 EVO on Amazon – a great deal at £90 for a 250GB solid state drive, or so I thought. A few days later, I was offered the chance to review the 850 EVO, and of course I couldn’t pass that up – especially as I now had the perfect means to see exactly what’s changed in the new generation.

The 850 Evo promises improved speeds and aggressive pricing thanks to its vertically stacked (3D) NAND. Today, we’ll find out if it’s a true improvement over the 840 series, or just marketing hype. Let’s go.

Specifications

Capacity	120GB	250GB	500GB	1TB
Controller	Samsung MGX	Samsung MGX	Samsung MGX	Samsung MEX
DRAM Cache	256MB	512MB	512MB	1GB
Sequential Read	540 MB/s	540 MB/s	540 MB/s	540 MB/s
Sequential Write	520 MB/s	520 MB/s	520 MB/s	520 MB/s
Random Read	94000	97000	98000 IOPS	98000 IOPS
Random Write	88000	88000	90000 IOPS	90000 IOPS
Price	£73.49	£109.99	£198.49	£367.49

Unboxing & Design

The Samsung 850 EVO comes in a pleasant white box, with the capacity marked and a proud ‘powered by 3D V-NAND Technology’ mention.

On the back, we have some assurances of “a new caliber of performance & endurance” and a nice “for review purpose only” sticker. Ooh, exclusive.

Inside the box, we find the SSD and the above – an installation guide, warranty statement and manual / driver CD.

Our first view of the SSD! It’s black, with Samsung written in white and Solid State Drive in grey. It’s the standard 2.5-inch size, of course.

The back is a little more exciting, showing various model numbers and regulatory information, as well as that 1TB capacity.

Finally, here’s a nice render of what the inside looks like.

That’s about it for design, so let’s move onto the fun part – testing!

Benchmarks

As there’s little real-world analysis to be done, we’ll be strictly in benchmark land for the majority of this article. We’ll be testing the two Samsung drives – and a third Corsair drive, the most recent that I’ve tested – in a battery of tests to see which is the fastest. All drives are empty for the tests, and Windows is run on another SSD.

The test rig has a Core i7 2600K processor and 16GB of RAM; the OS is Windows 10. Note that Samsung’s RAPID caching was not used for these tests, as it doesn’t appear to support Windows 10.

CrystalDiskMark

CrystalDiskMark has been one of my favourite benchmarks for evaluating storage speeds for a while now, thanks to its varied incompressible workload and extremely readable results. Here’s the 3.0.3 x64 version of the benchmark; all results are in MB/s.

CDM 3 Read	Seq	512K	4K	4K QD32
Samsung 850 Evo	513	472	38	408
Samsung 840 Evo	515	473	35	397
Corsair Neutron GTX	450	376	27	328

CDM 3 Write	Seq	512K	4K	4K QD32
Samsung 850 Evo	504	479	68	352
Samsung 840 Evo	500	390	86	313
Corsair Neutron GTX	480	468	69	158

In our first result, we see a fairly disappointing sign – the 850 provides only a marginal increase over the 840, with the only noticeable deltas coming in the 512K write test and 4K queue depth 32 test. Otherwise, the two drives are a stone’s throw from each other.

AS SSD Benchmark

AS SSD is another benchmarking tool quite similar to CrystalDiskMark, which uses predominantly incompressible data across a range of workloads including sequential tests, random performance and access times. First three numbers are MB/s and access time is in ms.

AS SSD Read	Seq	4K	4K QD64	Acc. Time	Score
Samsung 850 Evo	516	34	382	0.059	467
Samsung 840 Evo	513	32	330	0.059	413
Corsair Neutron GTX	507	25	334	0.068	N/A

AS SSD Write	Seq	4K	4K QD64	Acc. Time	Score
Samsung 850 Evo	497	66	299	0.051	415
Samsung 840 Evo	497	69	207	0.054	326
Corsair Neutron GTX	473	62	295	0.062	N/A

The biggest gains from the 840 to the 850 come in the higher queue depth sector, with the 850 recording scores 16% higher in the read test and 44% higher in the write test. Otherwise, the two drives are tough to separate, although both are better than the older Corsair drive.

ATTO Disk Benchmark

ATTO produces rather less comprehensible results than CrystalDiskMark, but still provides a good test of compressible data transfer. It also provides a lot of data points; I’ve selected six from across the range. Settings were the default: 256MB total length and queue depth of 4, testing from 1KB to 8MB. All results are in MB/s.

Atto Read	1KB	4KB	64KB	256KB	1MB	8MB
Samsung 850 Evo	80	269	538	551	558	558
Samsung 840 Evo	94	280	535	551	555	555
Corsair Neutron GTX	15	61	336	452	530	540

Atto Write	1KB	4KB	64KB	256KB	1MB	8MB
Samsung 850 Evo	83	255	519	529	534	534
Samsung 840 Evo	81	260	515	527	533	534
Corsair Neutron GTX	15	142	474	470	493	498

The two Samsung drives are near identical in these benchmark results, with the 840 taking a lead early on in the read test but losing out later on; in terms of write speeds the two drives are basically equivalent.

HD Tune Pro

We conclude with HD Tune Pro, a benchmark which produces three scores for average read speed, read access time, and burst read rate.

HD Tune Pro 5.50 Read	Average	Access Time	Burst Rate
Samsung 850 Evo	370 MB/s	0.044 ms	250 MB/s
Samsung 840 Evo	358 MB/s	0.041 ms	231 MB/s
Corsair Neutron GTX	340 MB/s	0.059 ms	231 MB/s

Here the Samsung 850 Evo shows its best results yet, with a small but noticeable lead in average read speed and burst read speed over its older brother.

Conclusion

While the Samsung 850 Evo proved both dependable and powerful across our battery of tests, I can’t help but be disappointed. I had expected a greater increase in performance from the new 3D NAND arrangement, instead of what amounts to marginal updates and even a few small regressions. While the difference in price is small, for the moment I’d advise that you go for the cheaper and more widely available 840 Evo models instead of these newcomers.

Pros

• Consistently fast performance across all workloads
• Low launch price, only ~20% more than the previous generation’s current price
• Improved performance in high queue depth tests

Cons

• Performance delta between 850 Evo and 840 Evo is small

Score

• 8 / 10