Samsung Reveals the 970 PRO & 970 EVO Generation M.2 SSDs

For the last several years running, Samsung has been at the forefront of raw NVMe M.2 solid-state drive performance, constantly expanding the performance envelope since the debut of the 950 PRO three years ago. Today that trend continues with the launch of the third-generation 970 Series powered by Samsung’s new “Phoenix” controller. As we’ve come to expect the PRO models will feature Samsung’s 64-layer MLC 3D V-NAND, while the EVO swaps the flash memory to more affordable TLC V-NAND.

The most notable changes over the previous generation are with the EVO lineup. Instead of the 960 EVO’s 3 year warranty, the 970 EVO bumps this up to a full five years which puts it on equal footing as the 970 PRO. This longer warranty wouldn’t be complete without a boost to the TBW (Total Bytes Written) rating, which also receives a 50% increase over the last-generation 960 models. Last and certainly not least, the EVO gains a substantial write performance jump with 3.4GB/s reads and 2.5GB/s writes quoted for the 1TB model.

Samsung clearly knows the 970 EVO’s will be the hotter selling drives, and has positioned its lineup accordingly, offering the more affordable 970 EVO in four capacities from 250GB up to 2TB. This contrasts with the 970 PRO, which will only be launching in performance-optimized 512MB and 1TB models.

The reason we aren’t seeing a 2TB 970 PRO is because the cost would make it prohibitively expensive compared to the existing 2TB EVO. Not to mention that when the 2TB EVO’s SLC fast-write cache scales up to 72GB, it would require monumental enterprise or server grade sustained workload to ever be exceeded.

Samsung has amped up the value on the 970 EVO, though there remains a few clear advantages to the 970 PRO to allow it to retain a premium status. For starters the PRO models are rated for twice the endurance as their EVO counterparts. Second, without the need for an SLC fast-write cache, the PRO drives are able to offer sustained write performance during very long sustained workloads.

Once the fast-write SLC cache is exhausted, EVO models will see a sharp decrease in write performance to the raw TLC speeds shown in the EVO table. That being said, we find it exceedingly hard to imagine anyone exhausting 36GB of cache on the 1TB model unless that person was a server sysadmin for a large organization!

This brings us to the final point of endurance. By utilizing a fast-write cache, the NAND is effectively writing the same data twice, and that fast-write cache of course does decrease the available starting capacity of the drive. Still, it remains hard to argue with the 970 EVO’s value, given the now identical five year warranty and very close performance ratings.