Kicking off a busy day in the SSD industry, today we're looking at the launch of Samsung's new 860 PRO SSD. The Samsung 860 PRO is an update to the venerable 850 PRO SATA SSD, and comes at a time where Samsung faces more serious competition than they have in several years, but also when the market has almost entirely moved on from premium SATA SSDs. The 860 PRO uses the latest 64L 3D MLC NAND and LPDDR4 DRAM from Samsung plus a new revision to their highly successful SATA SSD controller series. Accordingly, the latest PRO SSD from Samsung isn't meant to be a game-changer like its predecessor, but rather is a natural evolution of Samsung's SATA SSDs – at least as much as SATA SSDs can evolve. For the SATA SSD market then, the 860 PRO stands to be the latest, greatest, fastest, and possibly last(est) high-end desktop MLC SATA SSD that we'll ever see.

The Samsung SSD 850 PRO introduced 3D NAND flash memory to the consumer SSD market over three years ago. Since then, it has reigned as the top SATA SSD. The combination of Samsung's MLC 3D NAND and their top-notch SSD controller gave the 850 PRO performance and write endurance that were nearly unbeatable.

The SSD market now is very different from when the 850 PRO launched in mid-2014. All the attention for premium SSDs is now focused on the NVMe market where significant performance differentiation is possible. The mainstream SSD market has shifted to using TLC NAND instead of MLC NAND, first in the SATA segment and now even most NVMe SSDs are adopting TLC. At first, the switch to TLC was a race to the bottom that left the 850 PRO almost completely unchallenged. In 2016, Intel and Micron brought the second 3D NAND implementation to market, but their 32-layer 3D floating gate NAND flash proved to be slower (though cheaper) than Samsung's. In 2017, Toshiba and Western Digital/SanDisk finally produced 3D NAND suitable for the mass market, and the second-generation 3D NAND from Intel/Micron debuted. With 64-layer 3D NAND and more mature SSD controllers, these competitors have finally started to challenge the performance of the Samsung 850 PRO—usually while beating it on price.

Samsung hasn't been standing still. In addition to extending their dominance into the NVMe SSD market, Samsung has quietly updated the 850 PRO and 850 EVO without introducing new naming. In mid 2015, Samsung introduced 2TB models to both SATA families, and updated the controllers to support LPDDR3 DRAM instead of the LPDDR2 initially used by the 850s. Over the course of 2016, Samsung moved the 850s from their second-generation 32-layer 3D NAND to their third generation 48L 3D NAND. This brought a doubling of the capacity of each NAND die, and allowed Samsung to produce 4TB versions of the 850 PRO and EVO, though only the 4TB EVO actually made it to market.

Samsung 860 PRO Specifications
Capacity	256 GB	512 GB	1 TB	2 TB	4 TB
Form Factor	2.5" SATA 6 Gbps
Controller	Samsung MJX
NAND	Samsung 64-layer 3D MLC V-NAND
LPDDR4 DRAM	512 MB		1 GB	2 GB	4 GB
Sequential Read	up to 560 MB/s
Sequential Write	up to 530 MB/s
4KB Random Read	up to 100k IOPS
4KB Random Write	up to 90k IOPS
DevSleep Power	2.5 mW – 7 mW
Endurance	300 TBW	600 TBW	1200 TBW	2400 TBW	4800 TBW
Warranty	5 years
MSRP	$139.99 (55¢/GB)	$249.99 (49¢/GB)	$479.99 (47¢/GB)	$949.99 (46¢/GB)	$1899.99 (46¢/GB)

The changes the 860 PRO brings over the 850 PRO are pretty mundane. The controller has been updated again to support new memory: now codenamed MJX, it uses LPDDR4 DRAM. Samsung hasn't shared whether it deviates from their pattern of two or three ARM Cortex-R cores, nor what the clock speeds or fabrication process node are. The flash memory has been updated to Samsung's 64L 3D MLC, their fourth generation of 3D NAND. The Samsung 860 PRO is our first look at Samsung's 64-layer MLC V-NAND, after several encounters with the 64L TLC last year. Both 860 PRO models we have tested use 256Gb dies that are substantially larger than the 256Gb 64L TLC dies we have used previously.

The most visible change is that Samsung is finally launching the 4TB capacity in the PRO line. The 4TB model may turn heads, but it should not be mistaken for a mainstream product. It is a product born from the same mindset that leads to the GeForce Titan GPUs, Extreme Edition or Threadripper CPUs, and 1.5kW power supplies. The total available market for such products is tiny and often insufficient to justify creating the product. Instead, these parts are valuable for their "halo effect": Samsung's ability to offer a 4TB SSD helps their brand image even among consumers who cannot afford to spend anywhere near this much on their SSD.

Aside from the inclusion of the 4TB model, there is little to make the 860 PRO appear superior to the 850 PRO. Power consumption ratings have decreased slightly, but the limits of the SATA connection mean there is little room for performance improvement. The warranty period has dropped from the outstanding 10 years to a more typical 5 years. On the other hand, Samsung has stopped severely lowballing the write endurance rating. At every capacity, the 860 PRO's total write endurance rating is at least doubled, and given the shorter warranty period this yields a drive writes per day rating of 0.64, compared to a maximum of 0.16 DWPD over 10 years for the 850 PRO. The write endurance ratings are still lower than the enterprise PM863a to say nothing of the SM863a's 5.5 DWPD, but among consumer drives the 860 PRO's specified endurance no longer looks like a joke.

The other noteworthy recent MLC SATA drive is the Crucial BX300. This drive conveniently solved several problems for Micron. Since their 32L 3D NAND dies can be treated either as 384Gb TLC or 256Gb MLC, the BX300 gives Micron an outlet to sell dies that cannot meet the endurance requirements for use as TLC. At the same time, the smaller usable capacity of their MLC parts makes them more suitable for use in low-capacity SSDs. The Samsung 860 PRO isn't as convenient for Samsung to produce—they have little use for the 64L 256Gb MLC parts elsewhere in their product line so far, nor for a 384Gb TLC part.

There aren't any many SSDs to make a fair comparison against the Samsung 860 PRO, especially the 4TB model. This review includes test results from the 4TB 850 EVO and the 2TB 850 PRO, but otherwise focuses on comparisons in the 512GB capacity class. Those drives include:

• The Samsung 850 PRO 512GB: Our sample is one of the original generation using 32L 3D NAND and LPDDR2 DRAM, rather than the updated model with 48L 3D NAND and LPDDR3.
• The Intel 545s, using Intel's 64L 3D TLC and the Silicon Motion SM2259 controller
• The SanDisk Ultra 3D (unfortunately in the 1TB capacity) using SanDisk/Toshiba 64L 3D TLC and the Marvell 88SS1074 controller
• Three Crucial SSDs with Micron 3D NAND: the MX500 with 64L 3D TLC and the SM2258 controller, the MX300 with 32L 3D TLC and the Marvell 88SS1074 controller, and the BX300 with 32L 3D MLC and the SM2258 controller
• The Samsung PM981 512GB, a M.2 NVMe SSD for the OEM market, using 64L 3D TLC. A retail version of this is likely to be the successor to the Samsung 960 EVO, and the pricing will probably be on par with the 512GB 860 PRO. Thus, the PM981 illustrates the tradeoffs of sticking with the SATA interface and insisting on MLC NAND when cheaper TLC is good enough for almost all users.

The 860 PRO is going to be the most expensive SATA drive in this bunch, and even the one NVMe drive is probably not going to be much more expensive per gigabyte than the 860 PRO when its retail version arrives. Even without the legacy of the 850 PRO, the expectation would be for the 860 PRO to demonstrate clear superiority.

AnandTech 2017 SSD Testbed
CPU	Intel Xeon E3 1240 v5
Motherboard	ASRock Fatal1ty E3V5 Performance Gaming/OC
Chipset	Intel C232
Memory	4x 8GB G.SKILL Ripjaws DDR4-2400 CL15
Graphics	AMD Radeon HD 5450, 1920x1200@60Hz
Software	Windows 10 x64, version 1703
	Linux kernel version 4.14, fio version 3.1

• Thanks to Intel for the Xeon E3 1240 v5 CPU
• Thanks to ASRock for the E3V5 Performance Gaming/OC
• Thanks to G.SKILL for the Ripjaws DDR4-2400 RAM
• Thanks to Corsair for the RM750 power supply, Carbide 200R case, and Hydro H60 CPU cooler
• Thanks to Quarch for the XLC Programmable Power Module and accessories

AnandTech Storage Bench - The Destroyer

The Destroyer is an extremely long test replicating the access patterns of very IO-intensive desktop usage. A detailed breakdown can be found in this article. Like real-world usage, the drives do get the occasional break that allows for some background garbage collection and flushing caches, but those idle times are limited to 25ms so that it doesn't take all week to run the test. These AnandTech Storage Bench (ATSB) tests do not involve running the actual applications that generated the workloads, so the scores are relatively insensitive to changes in CPU performance and RAM from our new testbed, but the jump to a newer version of Windows and the newer storage drivers can have an impact.

We quantify performance on this test by reporting the drive's average data throughput, the average latency of the I/O operations, and the total energy used by the drive over the course of the test.

Samsung's dominance of this test wasn't being seriously challenged, but the 512GB 860 PRO does show improvement to the average data rate on The Destroyer, putting it up in the range of Samsung's multi-TB SATA drives. It's a small change, but SATA doesn't leave room for big gains.

The good average and 99th percentile latency scores of the SanDisk Ultra 3D match or beat the best scores from the Samsung SATA drives. The 512GB 860 PRO shows substantial improvement in 99th percentile latency and more modest gains in average latency, relative to the 850 PRO.

The Samsung 860 PROs show the best average read latencies in their respective product classes, but the SanDisk Ultra 3D isn't far behind. For average write latencies, the Ultra 3D takes a clear lead over the Samsung drives, and the Crucial BX300 is ahead of the Samsung drives by a hair.

The 99th percentile read and write latencies of the 860 PRO show substantial improvements at 512GB, and smaller improvements among the multi-TB drives.

While the 4TB 860 PRO performed better on The Destroyer than the 512GB model by every measure, the 512GB model was more power efficient, and sets a new record for its class. The improvements relative to the 850 PRO are remarkable: the old 512GB 850 PRO required 60% more energy to complete The Destroyer than the new 512GB 860 PRO. Samsung has caught up with the modern competitors in terms of energy efficiency.

AnandTech Storage Bench - Heavy

Our Heavy storage benchmark is proportionally more write-heavy than The Destroyer, but much shorter overall. The total writes in the Heavy test aren't enough to fill the drive, so performance never drops down to steady state. This test is far more representative of a power user's day to day usage, and is heavily influenced by the drive's peak performance. The Heavy workload test details can be found here. This test is run twice, once on a freshly erased drive and once after filling the drive with sequential writes.

As with The Destroyer, Samsung's SATA SSDs were still on top before the Samsung 860 PRO arrived. The 860 PRO brings only modest improvements to the average data rates on the Heavy test, and the 512GB models is slightly faster than the 4TB model. The only real outlier here is the Crucial MX300, for its poor performance when the drive is full.

The Samsung MLC SSDs and the SanDisk Ultra 3D offer the best average and 99th percentile scores among the SATA drives, but even the current models from Intel and Crucial are close enough to be indistinguishable without benchmarking tools.

Most of the drives show small differences in average read latency between the full and empty drive test runs, but it's the write latencies that account for the bulk of the delays experienced during this test. The Samsung 860 PROs are among the several drives that show virtually no difference in average write latency when the drive is full.

The 99th percentile read and write latency scores show that most of these SATA SSDs are equally competent at keeping latency under control. As usual, the Crucial MX300's full drive results stand out as particularly bad, and the BX300 is revealed to have a problem with high latency writes whether or not it is full.

The 860 PRO mostly eliminates the gap in power efficiency relative to the modern competitors. The 4TB model requires slightly more power than the 512GB, but is still a substantial improvement over the multi-TB 850s.

AnandTech Storage Bench - Light

Our Light storage test has relatively more sequential accesses and lower queue depths than The Destroyer or the Heavy test, and it's by far the shortest test overall. It's based largely on applications that aren't highly dependent on storage performance, so this is a test more of application launch times and file load times. This test can be seen as the sum of all the little delays in daily usage, but with the idle times trimmed to 25ms it takes less than half an hour to run. Details of the Light test can be found here. As with the ATSB Heavy test, this test is run with the drive both freshly erased and empty, and after filling the drive with sequential writes.

The Samsung SATA drives can mostly be distinguished from the other SATA drives by how much of their performance they retain when full; most of the competing drives show a bigger relative drop in average data rate. Between the Samsung drives, the differences are insignificant, and the peak performance of the competitors is pretty close to that of the Samsung drives.

The average and 99th percentile latency scores on the Light test show that most of these SATA drives perform almost identically, but the 860 PROs have smaller full-drive performance hits than the other drives.

The average read latencies on the Light test tend to be a bit lower than the write latencies when the test is run on an empty drive, but when the drives are full, the read latencies climb to be slightly higher than the write latencies. The Samsung SATA SSDs all show smaller performance hits from being full than most of the competing SATA SSDs.

The 99th percentile read latencies are in the 2-3ms range and the 99th percentile write latencies hover right around 3ms. The Crucial drives provide the biggest outliers, but even the 5-6ms response times of the MX300 aren't bad as a worst-case performance measure.

The 500 GB Samsung 850 EVO is once again the most efficient Samsung drive while the 860 PROs  improve upon the poor efficiency of the 850 PROs but don't entirely catch up to the competition.

Random Read Performance

Our first test of random read performance uses very short bursts of operations issued one at a time with no queuing. The drives are given enough idle time between bursts to yield an overall duty cycle of 20%, so thermal throttling is impossible. Each burst consists of a total of 32MB of 4kB random reads, from a 16GB span of the disk. The total data read is 1GB.

The 512GB Samsung 860 PRO has the fastest burst random read speed among these SATA SSDs, about 5% faster than the 850 PRO. The 4TB model is the same speed as the 4TB 850 EVO.

Our sustained random read performance is similar to the random read test from our 2015 test suite: queue depths from 1 to 32 are tested, and the average performance and power efficiency across QD1, QD2 and QD4 are reported as the primary scores. Each queue depth is tested for one minute or 32GB of data transferred, whichever is shorter. After each queue depth is tested, the drive is given up to one minute to cool off so that the higher queue depths are unlikely to be affected by accumulated heat build-up. The individual read operations are again 4kB, and cover a 64GB span of the drive.

On the longer random read test involving some higher queue depths, the Samsung 860 PROs take a clear lead, and the 4TB model even outperforms the PM981 NVMe SSD.

The two Samsung 860 PROs offer the same power efficiency, which is a huge step up from the 850 PRO's efficiency and significantly better than any of the competition.

Samsung 860 PRO 512GBSamsung PM981 512GBIntel SSD 545s 512GBSamsung 850 EVO 4TBSamsung 850 EVO 500GBSamsung 850 PRO 2TBSamsung 850 PRO 512GBSamsung 860 PRO 4TBCrucial BX300 480GBCrucial MX300 525GBCrucial MX500 500GBSanDisk Ultra 3D 1TB

Most of the Samsung drives hit the same limit of almost 400 MB/s around QD16. The two latest Crucial SSDs only just reach reach that level of performance at QD32, while the Intel 545s and Crucial MX300 never scale up that far. The PM981 NVMe drive scales far beyond any of the SATA drives, but at the cost of very poor power efficiency, especially at lower queue depths.

Random Write Performance

Our test of random write burst performance is structured similarly to the random read burst test, but each burst is only 4MB and the total test length is 128MB. The 4kB random write operations are distributed over a 16GB span of the drive, and the operations are issued one at a time with no queuing.

The 4TB 860 PRO has the fastest burst random write speed, while the 512GB model scores slightly worse than the 512GB 850 PRO.

As with the sustained random read test, our sustained 4kB random write test runs for up to one minute or 32GB per queue depth, covering a 64GB span of the drive and giving the drive up to 1 minute of idle time between queue depths to allow for write caches to be flushed and for the drive to cool down.

The sustained random write performance of the Samsung 860 PRO is a very slight improvement over their previous drives. Most of the competition is significantly slower on this test, but the Crucial BX300 is pretty close.

The Samsung 860 PROs are again the two most efficient SATA SSDs, and the 512GB model manages to match the efficiency of the much faster but more power hungry PM981.

Samsung 860 PRO 512GBSamsung PM981 512GBIntel SSD 545s 512GBSamsung 850 EVO 4TBSamsung 850 EVO 500GBSamsung 850 PRO 2TBSamsung 850 PRO 512GBSamsung 860 PRO 4TBCrucial BX300 480GBCrucial MX300 525GBCrucial MX500 500GBSanDisk Ultra 3D 1TB

The 860 PRO reaches full random write speed at QD4 and is steady through the rest of the test. The Crucial MX500 and Intel 545s are much slower to get up to speed, and the SanDisk Ultra 3D plateaus at a mere 200MB/s after QD2.

Sequential Read Performance

Our first test of sequential read performance uses short bursts of 128MB, issued as 128kB operations with no queuing. The test averages performance across eight bursts for a total of 1GB of data transferred from a drive containing 16GB of data. Between each burst the drive is given enough idle time to keep the overall duty cycle at 20%.

The burst sequential read speeds of the 860 PROs are good but not record setting, and the differences between the SATA drives are all dwarfed by the performance of the NVMe drive.

Our test of sustained sequential reads uses queue depths from 1 to 32, with the performance and power scores computed as the average of QD1, QD2 and QD4. Each queue depth is tested for up to one minute or 32GB transferred, from a drive containing 64GB of data.

With the exception of the 500GB 850 EVO, all of the Samsung SATA drives in this bunch offer about the same sustained sequential read speed. These drives have a substantial advantage over the competing drives, which are led by the Intel 545s at about 85 MB/s slower than the 860 PRO.

The two Samsung 860 PROs have the clear lead for power efficiency during sequential reads, above even the fast PM981 NVMe drive.

Samsung 860 PRO 512GBSamsung PM981 512GBIntel SSD 545s 512GBSamsung 850 EVO 4TBSamsung 850 EVO 500GBSamsung 850 PRO 2TBSamsung 850 PRO 512GBSamsung 860 PRO 4TBCrucial BX300 480GBCrucial MX300 525GBCrucial MX500 500GBSanDisk Ultra 3D 1TB

The sequential read speed of the Samsung 860 PROs starts out quite close to the SATA limit, but they don't actually reach it until QD4. After that point, they are completely steady while the competing drives tend to be both slower and less consistent.

Sequential Write Performance

Our test of sequential write burst performance is structured identically to the sequential read burst performance test save for the direction of the data transfer. Each burst writes 128MB as 128kB operations issued at QD1, for a total of 1GB of data written to a drive containing 16GB of data.

Both models of the Samsung 860 PRO show a bit of a regression on the burst sequential write test, with the 4TB 860 PRO coming in at 13 MB/s slower than the 4TB 850 EVO, and the 512GB 860 PRO is behind the 512GB 850 PRO by twice that margin.

Our test of sustained sequential writes is structured identically to our sustained sequential read test, save for the direction of the data transfers. Queue depths range from 1 to 32 and each queue depth is tested for up to one minute or 32GB, followed by up to one minute of idle time for the drive to cool off and perform garbage collection. The test is confined to a 64GB span of the drive.

The sustained sequential write speeds of the Samsung 860 PRO are slightly lower than some of the 850s, but not noticeably. Only the Intel 545s and SanDisk Ultra 3D are slow enough to really care about.

The power efficiency of the 860 PRO continues to be a huge improvement over the 850s, with the 512GB 860 PRO taking a big lead over everything else in its class.

Samsung 860 PRO 512GBSamsung PM981 512GBIntel SSD 545s 512GBSamsung 850 EVO 4TBSamsung 850 EVO 500GBSamsung 850 PRO 2TBSamsung 850 PRO 512GBSamsung 860 PRO 4TBCrucial BX300 480GBCrucial MX300 525GBCrucial MX500 500GBSanDisk Ultra 3D 1TB

Most of the SATA drives are at full speed by QD2 or QD4, but the SanDisk Ultra 3D takes a bit longer to get up to speed and the Crucial MX300 can't maintain that speed. Once they've all (mostly) plateaued at the same performance level, it is clear that the 860 PRO requires less power than any of its competitors or predecessors.

Mixed Random Performance

Our test of mixed random reads and writes covers mixes varying from pure reads to pure writes at 10% increments. Each mix is tested for up to 1 minute or 32GB of data transferred. The test is conducted with a queue depth of 4, and is limited to a 64GB span of the drive. In between each mix, the drive is given idle time of up to one minute so that the overall duty cycle is 50%.

The Samsung 860 PRO is the fastest SATA SSD on our mixed random I/O test, with the 4TB model scoring slightly better than the 512GB model. This is a big improvement over the multi-TB 850s which were substantially slower than the half-TB models.

The 850 PRO is again the most efficient drive in the bunch, but the 512GB model is clearly more efficient than the 4TB despite being a bit slower.

Samsung 860 PRO 512GBSamsung PM981 512GBIntel SSD 545s 512GBSamsung 850 EVO 4TBSamsung 850 EVO 500GBSamsung 850 PRO 2TBSamsung 850 PRO 512GBSamsung 860 PRO 4TBCrucial BX300 480GBCrucial MX300 525GBCrucial MX500 500GBSanDisk Ultra 3D 1TB

At every stage of the mixed random I/O test, the 860 PRO draws less power than any of its competitors and it is only outperformed by the 4TB model and momentarily by the 512GB 850 PRO.

Mixed Sequential Performance

Our test of mixed sequential reads and writes differs from the mixed random I/O test by performing 128kB sequential accesses rather than 4kB accesses at random locations, and the sequential test is conducted at queue depth 1. The range of mixes tested is the same, and the timing and limits on data transfers are also the same as above.

Neither capacity of the Samsung 860 PRO quite manages to top the performance of the 4TB 850 EVO on the mixed sequential test, but they're close enough.

The power efficiency gap between the 860 PROs and the rest of the SATA SSDs is huge. The 512GB model takes first place, and the 4TB model is tied with the PM981 for second place efficiency.

Samsung 860 PRO 512GBSamsung PM981 512GBIntel SSD 545s 512GBSamsung 850 EVO 4TBSamsung 850 EVO 500GBSamsung 850 PRO 2TBSamsung 850 PRO 512GBSamsung 860 PRO 4TBCrucial BX300 480GBCrucial MX300 525GBCrucial MX500 500GBSanDisk Ultra 3D 1TB

Samsung's SSDs tend to show lower performance during the second half of this test when the workloads are more write-heavy. The 860 PRO continues this pattern, but with very shallow performance dips.

Power Management

Real-world client storage workloads leave SSDs idle most of the time, so the active power measurements presented earlier in this review only account for a small part of what determines a drive's suitability for battery-powered use. Especially under light use, the power efficiency of a SSD is determined mostly be how well it can save power when idle.

SATA SSDs are tested with SATA link power management disabled to measure their active idle power draw, and with it enabled for the deeper idle power consumption score and the idle wake-up latency test. Our testbed, like any ordinary desktop system, cannot trigger the deepest DevSleep idle state.

Idle power management for NVMe SSDs is far more complicated than for SATA SSDs. NVMe SSDs can support several different idle power states, and through the Autonomous Power State Transition (APST) feature the operating system can set a drive's policy for when to drop down to a lower power state. There is typically a tradeoff in that lower-power states take longer to enter and wake up from, so the choice about what power states to use may differ for desktop and notebooks.

We report two idle power measurements. Active idle is representative of a typical desktop, where none of the advanced PCIe link or NVMe power saving features are enabled and the drive is immediately ready to process new commands. The idle power consumption metric is measured with PCIe Active State Power Management L1.2 state enabled and NVMe APST enabled.

In addition to load power efficiency improvements, the 860 PRO brings modest improvements to  idle power consumption. Samsung's active idle power consumption was already pretty good, but the 860 PRO provides further savings. The idle power in slumber state is a big improvement for both of the 860 PROs, likely due to the use of LPDDR4.

The idle wake-up latency of Samsung's drives hasn't changed, and is still hovering just above 1ms.

Conclusion

By the numbers, the Samsung 860 PRO is generally the fastest SATA SSD, but the performance doesn't stand out from the crowd. The 860 PRO offers only slight improvements over the performance of the 850 PRO, and the better competing SATA SSDs are now able to perform at or near the level of the Samsung drives. The SATA interface is simply too much of a bottleneck for any SATA drive to distinguish itself with high performance on a broad range of tests. Hitting those limits is now expected from mainstream drives, instead of being an aspirational goal. Which means that while the 860 PRO is launching as the fastest SATA SSD on the market – once again retaining Samsung's traditional dominance of the market – its accomplishments feel mooted by the limitations of the SATA interface and how close the rest of the competition is these days.

The power consumption situation is quite different; there's plenty of room for improvement, and the 860 PRO delivers. The 850 PRO had been looking rather power-hungry lately as other drives approached its performance level without having to sacrifice as much power efficiency. With updated NAND and DRAM and controller, the 860 PRO is much more efficient than the 850 PRO, setting new records on tests where the Samsung drives still rated well, and catching up to most of the competition where the 850 PRO was notably inefficient.

The only aspect in which the Samsung 860 PRO has a clear and large advantage over the competition is the write endurance. The problem is that this does not matter. With the warranty period shortened to 5 years and the rated write endurance increased substantially over the 850 PRO, the 860 PRO's endurance rating comes out to 0.64 drive writes per day. It is genuinely hard to come up with a realistic non-server workload that produces a write volume equivalent to filling the entire drive every business day. Working with uncompressed video can certainly generate the terabytes of data needed to wear down an 860 PRO, but then the SATA bottleneck becomes significant. It may turn out that the only sensible reason to use an 860 PRO would be in a RAID array, and even then enterprise SSDs may offer a better balance of capacity, endurance, per-drive performance and cost.

SATA SSD Price Comparison
	240-275GB	480-525GB	960-1050GB	2TB	4TB
Samsung 860 PRO (MSRP)	$139.99 (55¢/GB)	$249.99 (49¢/GB)	$479.99 (47¢/GB)	$949.99 (46¢/GB)	$1899.99 (46¢/GB)
Samsung 860 EVO (MSRP)	$94.99 (38¢/GB)	$169.99 (34¢/GB)	$329.99 (33¢/GB)	$649.99 (32¢/GB)	$1399.99 (35¢/GB)
Samsung 850 EVO	$102.44 (41¢/GB)	$139.99 (28¢/GB)	$299.99 (30¢/GB)	$649.33 (32¢/GB)	$1427.95 (36¢/GB)
Samsung 850 PRO	$141.00 (55¢/GB)	$217.99 (43¢/GB)	$429.99 (42¢/GB)	$892.09 (44¢/GB)
Crucial MX500	$79.99 (32¢/GB)	$134.95 (27¢/GB)	$259.99 (26¢/GB)	$499.99 (25¢/GB)
Crucial BX300	$87.99 (37¢/GB)	$144.99 (30¢/GB)
Crucial MX300	$89.99 (33¢/GB)	$146.99 (28¢/GB)	$267.00 (25¢/GB)	$549.99 (27¢/GB)
SanDisk Ultra 3D	$79.99 (32¢/GB)	$129.99 (26¢/GB)	$249.99 (25¢/GB)	$499.99 (25¢/GB)
WD Blue 3D NAND	$79.99 (32¢/GB)	$139.99 (28¢/GB)	$274.79 (27¢/GB)	$556.00 (28¢/GB)
Toshiba TR200	$79.99 (33¢/GB)
Intel 545s	$99.99 (39¢/GB)	$159.99 (31¢/GB)

For more typical desktop and workstation usage patterns, the high endurance ratings of the Samsung 860 PRO are overkill, and so are the smaller ratings on the 860 EVO. Now that said – and least we see the pendulum swing the other way – having drives with plenty of write endurance is by and large a good thing, if only because it provides plenty of headroom for certain workloads and and some additional options on the market. The flip side of that however is that practically speaking, Samsung is offering a benefit that consumers don't need, and charging a substantial premium for it.

Ultimately the Samsung 860 PRO is a commendable technical achievement; Samsung has pushed the SATA III interface to its limit by having it serve such a powerful SSD, and it's entirely possible we won't see a better desktop SATA SSD ever made. But as SSDs get faster and faster and the SATA interface does not, I would argue that the 860 PRO isn't a very good product, at least not for the desktop SSD market of 2018. The market has moved on, and power users and enthusiasts who want something better than a mainstream SSD are all looking for PCIe SSDs. The Samsung 860 PRO is priced like a PCIe SSD, but offers none of the tangible advantages. And with the prices Samsung is planning on charging for the 860 family, I'm worried that at MSRP, even the 860 EVO is likely to be unconvincing.