Samsung 950 Pro review – NVMe reaches the mainstream

SSDs have gone from expensive and enthusiast-only to an affordable mainstream alternative to traditional hard disks in just a few short years. The transition has been so fast, and the increase in performance so drastic, that the SATA interface simply can’t keep up. NVMe, or Non-Volatile Memory Express, is the SSD specification set to replace it.

SATA was designed for mechanical storage and even the fastest SATA3 iteration is limited to a theoretical maximum throughput of 600MB/s. NVMe, meanwhile, operates over PCI-Express and was designed from the ground up to make the most of the low latency of flash storage. It has no such throughput limitations, letting compatible SSDs reach much higher read and write speeds.

NVMe was previously only supported by Intel’s enthusiast-only X99 motherboards, which are reserved for prohibitively expensive Haswell-E processors. Now that the Skylake platform has arrived, though, the standard looks set to quickly become the norm – making it the perfect time for Samsung to launch its first NVMe SSD.

The 950 PRO is the result. It reads and writes data across four PCI-Express 3.0 lanes using the NVMe protocol to deliver massive read and write speeds. It also shuns the familiar 2.5in SSD format in favour of the M.2 interface, a much smaller package that will fit comfortably in ultra-thin laptops as well as desktop PCs.

The M.2 2280 form factor makes this one of the largest M.2 SSDs available, but it should still fit on any X99 or Z170 motherboard. Importantly, these are the only motherboards that support booting from PCI-Express-based M.2 storage. While you could use a PCI-Express add-in card to install the 950 PRO on a different motherboard, you wouldn’t be able to use it to boot into Windows. Samsung doesn’t make an official add-in card, either.

With no standardisation when it comes to motherboard layout, the location of your M.2 slot will vary between manufacturers; some companies place the slot on the rear of the motherboard, while others squeeze it in between the PCI-Express slots usually reserved for graphics cards. Either way, if you’re planning on adding the 950 PRO to an existing system, you’ll probably need to remove a component or two in order to reach the storage slot.

The SSD itself is mostly comprised of Samsung’s second-generation, 32-layer MLC V-NAND flash storage chips, arranged in 128GB modules, with space for the UBX controller alongside them. The V-NAND modules are stacked vertically to fit in a smaller space, and in turn use less power than 2D planar NAND. M.2 SSDs draw power directly from the motherboard, unlike SATA drives which need separate SATA power and data cables. In a desktop PC, this will free up space inside the case and stop cables from obstructing airflow.

Speed is, of course, the biggest reason for making the switch to NVMe, and it’s here that the 950 PRO truly delivers. It exceeded Samsung’s claims of 900MB/s writes and 2,200MB/s reads in the ATTO synthetic storage benchmark, producing 958MB/s and 2,297MB/s respectively.

Real-world file transfers don’t necessarily match up to synthetic tests, but the 950 PRO continued to impress in our custom storage benchmarks. We run these under Windows 10, and so the tests are affected by features such as write caching. In our huge files test, which uses files a gigabyte in size, we saw an incredible 1,349MB/s write and 2,171MB/s read speeds. This makes write speeds more than twice as fast as a SATA SSD, and read speeds almost four times as fast – there’s simply nothing else out there that can match this drive for the price.

This phenomenal performance continued in the large files test, where the 950 Pro managed similar 1,349MB/s writes and 2,064MB/s reads. The small files test is typically tougher, but 1,205MB/s writes and 1,646MB/s read speeds are still exceptional.

Although we’ve seen incredibly fast solid state storage before, most notably as Intel’s 750 series range, you needed an empty PCI-Express x4 slot on your motherboard to get the maximum performance. Now that NVMe support is becoming more common, SSDs like the 950 PRO makes a lot of sense.

If you’ve got a system that can take advantage of its speeds, the 950 PRO is absolutely worth the premium over a SATA SSD. The 256GB model in particular is phenomenal value compared to Intel’s PCI-Express-based SSDs, which cost significantly more for similar performance. You also get Samsung’s industry-leading five-year warranty, which guarantees each 256GB drive for up to 200 terabytes written (TBW).

Anyone with an older PC will have to hold off for now, but those investing in Intel’s Skylake CPUs or a top-end Haswell-E system have a new must-have component to add to their shopping list.