Samsung 4TB 850 Evo SATA III SSD

2016-07-25 • SEND FEEDBACK •
Related: Other World Computing, Samsung, SSD, storage, Thunderbolt, weather events

Samsung 4TB 850 Evo SATA III SSD

Get Samsung SSD at MacSales.com.

Thanks to B&H Photo for loaning the Samsung 850 EVO 4TB SSD for testing.

MPG reviewed the Samsung 850 EVO 2TB 2.5" SSD in late 2015. In July 2016, Samsung debuted the 850 EVO 4TB. At about $1499.99, it offers a huge amount of fast and silent storage capacity, albeit at a per-terabyte cost premium over lower capacity SSDs (the OWC Mercury Electra MAX 6G 2TB is about $598 as this was written).

The Samsung 850 EVO 4TB 2.5" SSD is a consumer-grade SSD (non enterprise) whose huge capacity holds great appeal for those looking for a lot of fast storage. Laptop users, users of devices like the OWC Thunderbay 4 Mini, OWC Thunderbolt Dock, etc. The 850 EVO is not an SSD designed to take a pounding 24X7 in a server environment or heavy usage environment, but rather as a device for storing a lot of data with very good performance. Its price and capacity are appealing for that purpose.

• 4TB Storage Capacity
• SATA III 6 Gb/s Interface compatible with SATA 3 Gb/s & SATA 1.5 Gb/s interface
• 2.5" Form Factor
• Up to 540 MB/s Sequential Read Speed
• Up to 520 MB/s Sequential Write Speed
• Samsung MHX Controller
• 256-Bit AES Encryption
• TRIM Support
• 3D V-NAND Technology
• TurboWrite Technology
• Random read: 4 KB QD32 Up to 98,000 IOPS, 4 KB QD1 Up to 10,000 IOPS
• Random write: 4 KB QD32 Up to 90,000 IOPS, 4 KB QD1 Up to 40,000 IOPS
• TRIM Support
• AES 256-bit Encryption (Class 0), TCG/Opal, MS eDrive IEEE1667 (Encrypted drive)
• Power Consumption (max): Active Reads: 3.7 W, Active Writes: 4.4 W, Idle: 0.5 W
• Reliability (MTBF): 2 million hours
• Annualized Failure Rate (AFR) 0.45%
• Reliability (TBW) 150 TBW / 80 GB
• Uncorrectable Bit Error Rate: 1 sector per 1017 bits read
• Operating Temperature: 32°F to 158°F / 0 to 70° C
• Humidity: 5 to 95%, non-condensing
• Data Retention 1 year power-off once SSD reaches rated write endurance at 104°F / 40°C

Controller and flash

The Samsung 850 EVO uses 3D V-NAND flash, which is not as robust as MLC flash. V-NAND technology was designed to handle a 40GB per day workload, which after ten years equates to 150 Terabytes written.

To put that in context, a single disktester fill-volume as shown here writes the entire drive (2000GB), and thus equates to forty (40!) days of rated use. Since the test was run three times just for the fill-volume test alone, that equates to 120 days of usage—in one day. As another example, saving a 4GB Photoshop file just 10 times a day equates to a full day’s usage, and yet your author (Lloyd) regularly saves files up to 10GB and often 5/10/20 files of size 2/4/5/6 GB each, and saves them several times typically. So 40GB/day rates usage is not a particularly durable design in terms of a Photoshop user who regularly works with big files. Still, most users are not likely to do nearly that much writing.

4TB Samsung 850 EVO as formatted in Apple Disk Utility, using OWC Thunderbolt Drive Dock

Capacity is a smidgen over 4TB = 3725.7 TiB.

4TB Samsung 850 EVO

Performance

Sustained transfer speed

Tested in the OWC Thunderbolt Drive Dock using the Thunderbolt port.
Performance testing by DiskTester, part of diglloydTools. Speeds are real-world throughput through the OS X file system.
disktester fill-volume

One can’t ask for faster or more consistent performance in a SATA SSD.

The write speed is incredibly consistent, particularly considering that the entire 4TB capacity was written without pause. The read speed is just about as good; the deviation is on the order of 2%—superb.

Write: 488 MiB/sec = 512 MB/sec
Read: 513 MiB/sec = 538 MB/sec

Incompressible data was also tested with the same results—no difference in performance.

Transfer speed vs transfer size of 4TB Samsung 850 EVO
in OWC Thunderbolt Drive Dock, late 2015 iMac 5K

Transfer speed vs transfer size

Tested in the OWC Thunderbolt Drive Dock using the Thunderbolt port.
Performance testing by DiskTester, part of diglloydTools. Speeds are real-world throughput through the OS X file system.
disktester run-sequential-suite -s 16K -e 512M --iterations 5 --test-size 4G

This is about as good as it gets for a SATA SSD. The Samsung EVO 4TB SSD offers very good performance right at 32K transfers, and reaches almost peak performance with 1MB transfers.

Perspective: the PCIe-based internal flash drive of the late 2013 Macbook Pro Retina delivers about 320-350 MiB/sec for 32 KiB transfers; it has a direct PCIe bus that lowers overhead. The 2015 MacBook Pro does far better, an incredible 700 MiB/sec for 32 KiB transfers. The late 2013 Mac Pro (Jan 2014 model, also PCIe) delivers only about 250 MiB/sec for 32 KiB transfers.

Speeds are MiB/sec; multiply by (1024/1000)^2 = 1.048576 for MB/sec.

Transfer speed vs transfer size of 4TB Samsung 850 EVO
in OWC Thunderbolt Drive Dock, late 2015 iMac 5K

Conclusions

The Samsung 4TB 850 Evo SATA III SSD offers an appealing combination of capacity and performance. The about $1500 price is high on a per-terabyte basis*, but it is a single drive on which an enormous amount of data can be stored and for most purposes the performance will not limit anything.

* The OWC Mercury Electra MAX 6G 2TB is about $598 as this was written, so 4TB is about $1196. The Samsung thus comes at a premium price on a price/capacity basis. But it delivers 4TB in a single drive.