Samsung 870 EVO SATA III SSD 1TB Review

“Best-in-Class Performance”

Samsung promises nothing less than the highest performance in its class with the 870 Evo, which is thus supposed to live up to its predecessors. On paper, the differences to the 860 Evo are marginal with 10 MB/s more in sequential read/write and thus 560/530 MB/s in the peak, the interface’s limit in read has long been reached. More significant differences are said to be seen in random read, which, according to Samsung, means up to 38 percent more performance with a practical command queue of QD1 (“Queue Depth”). According to Samsung, this is noticeable in trace benchmarks like PCMark Vantage, which simulate everyday use.

In addition, the 870 Evo is said to not drop as quickly under permanent load (“4K random writes”), there is talk of a 30% increased “sustained performance” compared to the 860 Evo, but this only applies to the comparison of the 250 GB models (see picture above).

Some users have suffered from performance drops during long-lasting workloads. The 870 EVO offers about 30% 1) better sustained performance compared to the 860 EVO, which has been proven in long-term writing tests. The 870 EVO delivers much more stable performance, so users experience consistently better performance.

1) For the 250 GB capacity model

At 2 TB, the SLC mode lasts twice as long.

Unchanged compared to the predecessor is the model range, which also means storage capacities of 250 GB, 500 GB, 1 TB, 2 TB and 4 TB for the 870 Evo. The write accesses are accelerated as usual via an SLC mode, which first writes the memory cells with only 1 bit before the data is then archived with 3 bits. Samsung calls the technology TurboWrite. As in the 860 Evo, this is divided into a permanently allocated and always available “default cache” and a “intelligent cache” that is dynamically linked to the available storage space.

Pseudo-SLC cache (TurboWrite) in the Samsung 870 Evo

A direct comparison with the 860 Evo shows that Samsung has doubled the intelligent SLC cache of the 2 TB model to 72 GB in the 870 Evo. However, this is not really necessary from a write speed perspective, because the 870 Evo with 1 TB, 2 TB and 4 TB are supposed to write with a full 530 MB/s even after the SLC cache. The test will confirm that the 2 TB model acts quasi equally fast in 1-bit and 3-bit mode. The two smaller variants with 250 GB and 500 GB then break down to 300 MB/s. The 860 Pro with MLC had tangible advantages here two years ago. An 870 Pro as successor is currently not in sight, the 860 Pro will be continued for now.

However, the smaller TLC SSDs also remain comparatively fast after the “cache”. The write rates after SLC mode were quite different in the QLC-SSDs of Samsung’s QVC series, which drop from over 400 MB/s write performance to under 100 MB/s after SLC mode, which quickly turns larger write processes into a test of patience.

The warranty remains at five years, but expires prematurely when the write volumes (“Total Bytes Written”, TBW) named by Samsung are exceeded. The TBW of 150 to 2,400 TB are also on par with the predecessor and are significantly higher than in the 870 QVO with less durable QLC NAND.

870 Evo with M.2 not in planning

The editors’ question whether a Samsung 870 Evo in the M.2 form factor is also to be expected was answered in the negative. Currently, no 870 Evo M.2 is planned, but the 860 Evo in M.2 format is to be continued instead.