Samsung 850 Evo

We were fans of the Samsung 840 Evo series of solid-state drives, as these were the first SSDs we saw to provide capacities up to 1TB. The 850 Evo is the follow-up, and is an SSD that uses Samsung’s new 3D V-NAND technology.

3D V-NAND refers to how the manufacturer stacks the cells in its NAND flash chips both vertically and horizontally, allowing for greater-capacity SSDs without having to shrink the manufacturing process, which is becoming increasingly difficult to achieve. 3D V-NAND chips use a 40nm process rather than the 20nm process more commonly seen in other manufacturers’ SSDs.

Although 3D V-NAND should pave the way for higher-capacity SSDs, the 850 Evo range still tops out at 1TB; a similar maximum to rival ranges from Crucial and SanDisk. Samsung does claim that 3D V-NAND has less cell-to-cell interference, which will help the cells last longer, and the technology should lead to higher-capacity SSDs in the future.

The disks in the 850 Evo range all use Samsung MGX controllers, save for the 1TB model, which has a Samsung MEX model. We tested the 250GB, 500GB and 1TB versions of the 850 Evo and performance was almost identically impressive across all the drives.

With the 250GB drive we saw large file write speeds of an astonishing 713.5MB/s. Large file read speeds were less impressive, but still above average at 464.7MB/s. Similarly, the 1TB drive managed a write speed of 712.9MB/s and 465.3MB/s in the large file read test. In our small file test the 1TB drive was the quickest model, with 95.5MB/s write and 99.8MB/s read speeds. Overall small file speeds were around average for all three drive capacities.

There’s no upgrade kit supplied with the drive, nor is one available as an optional bundle. Samsung also hasn’t included a spacer to help fit the drive in 9.5mm-high laptop drive bays, which is a shame. Samsung does provide Samsung Data Migration and Samsung Magician software. The former will make it easy to clone from an existing drive, but you might have to use your own SATA to USB cable if you don’t have a spare SATA cable. Samsung Magician provides a number of useful tools for optimising the disk drive, upgrading the firmware and monitoring the drive’s health. The software is straightforward and easy to use.

The 850 Evo’s large-file write speeds are seriously impressive, making this drive a rival for the Crucial M550. The various disks in both drive ranges are a similar price per gigabyte, but the Crucial drive is a faster drive overall, and so just wins out at current pricing. For all our current best Buy SSDs see our regularly updated Best SSD article.