Samsung 850 Evo 500GB

A decent SATA drive as far as it goes – but, if you’ve got an M.2 slot, there’s no need to settle for such mediocre speeds

No, it’s not a typo. The Samsung 850 Evo is a modern M.2 SSD, and it’s also a traditional SATA drive ( see right). It makes a bit more sense when you realise that the two drives are internally identical. The second notch on the M.2 connector betrays the fact that – like the Adata Ultimate SU800 ( see opposite) – the 850 Evo uses a regular SATA connection over PCI-E, rather than taking advantage of the faster NVMe standard.

As a result, the M.2 version of the 850 Evo is disappointing in exactly the same way as the SU800. Its performance figures are absolutely fine – for a SATA drive. By M.2 standards, they’re pretty disastrous. Sequential read and write operations tick along at less than half the speed you’d get from even the slowest NVMe drives. The only good news is that, as we saw with the Adata drive, SATA over M.2 seems to benefit multithreaded random writes: here, the M.2 850 Evo proved faster than any 2.5in SSD.

To be fair to Samsung, the 850 Evo M.2 isn’t a rip-off: it’s priced almost identically to the SATA version, working out at 31p per GB for the 500GB version. You also get hardware encryption, and Samsung’s likeable migration software – so, if you want an affordable SSD without giving up a SATA connector, this could be a decent answer. Honestly, though, we’re not sure we see the point.