Samsung EVO 850 M.2 review

M.2 is a new form factor that’s quickly becoming the standard storage interface for tablets and Ultrabook laptops, replacing mSATA. Samsung’s EVO 850 M.2 is one of the first consumer-friendly M.2 SSDs we’ve seen; it’s essentially a regular EVO 850 SSD squeezed onto a circuit board the size of a cigarette lighter.

This means it has the same Samsung-made MGX controller and 3D V-NAND flash memory as the standard EVO 850. In 3D V-NAND memory cells are stacked vertically so more fit in a smaller space; V-NAND is claimed to be around 30% more energy-efficient than 2D NAND. This makes it ideal for Ultrabook users looking to add some extra storage space, where it’s important to use as little power and to produce as little heat as possible.

M.2 SSDs are absolutely tiny compared to a regular 2.5in disk

It’s easy to upgrade the storage in desktop PCs and most larger laptops, but Ultrabooks are a different matter. Many of these thin laptops use circuit board-mounted flash memory instead of traditional SSDs, which makes them trickier to upgrade. There’s also a lot of variety in terms of whether Ultrabooks use the mSATA format rather than M.2, so it’s worth checking whether your laptop is compatible before you buy. You may also need special tools to open your laptop; all the Ultrabooks we have in the office need a Torx screwdriver to access the internals.

Once you get that far, you’ll also need some way of imaging your old SSD onto the EVO 850, as there isn’t an upgrade kit included in the box. External SATA to USB3 adaptors are available for around £35 (such as the SM2NGFFMBU33 from uk.startech.com), which you can use with cloning software such as EaseUS Disk Copy, but you’ll have to factor the price of the enclosure into your upgrade.

External enclosures like this Startech model will let you upgrade PCs that lack M.2 support

Samsung claims the EVO 850 M.2 is capable of 540MB/s read and 500MB/s write speeds, which should make it significantly faster than the M.2 SSDs that ship with many Ultrabooks. Amazingly, it managed to exceed that claimed write speed in our large file test, producing a fantastic 579.8MB/s. Read speeds weren’t quite as fast, but 436.1MB/s is still a rapid result. The read/write average puts the M.2 on par with many full-size SSDs.

Our small files test is always more demanding, but 108.1MB/s write and 85.4MB/s read speeds are still highly impressive. Taking into account large and small file speeds, this is one of the fastest SSDs we’ve tested, M.2 or otherwise.

M.2 SSDs aren’t just aimed at laptop users, either. A growing number of desktop motherboards come with M.2 slots, making the EVO 850 a feasible alternative to a standard 2.5in SSD if you’re building a PC in a compact chassis and have limited room for upgrades, or simply want to reduce the number of cables running through your case.  

The lack of any tools or software in the box might make it a fiddly upgrade for Ultrabook users, but the EVO 850 M.2 is seriously fast and worth the effort. If you’re building a clutter-free desktop PC, however, it’s ideal – as long as you have a compatible motherboard.