Western Digital WD_BLACK SN770 NVMe SSD 1TB, M.2

Mit der WD_Black SN770 erweitert Western Digital seine High-End-Serie um ein neues Modell, das bereits vom Namen her nicht mit der Top-SSD der Serie, der SN850, konkurrieren soll, sondern eher als Brückenschlag zwischen den Top-Modellen zu sehen ist. Dabei vermischt der Speicherspezialist Attribute der bisherigen Budget-Reihe "Blue" mit denen der Spitzenserie "Black". Ob diese Mixtur so funktioniert und für wen die WD_Black SN770 daher eine interessante SSD sein könnte, klären wir wie gewohnt mit unserem Review.

With the WD Black SN770, WD is modernizing their DRAM-less M.2 "Black" SSD offering. While the previous models used PCI-Express 3.0 with controllers from WD/Phison, and older 64 or 96-layer Toshiba NAND flash, the SN770 uses a brand-new controller that supports PCI-Express 4.0, and the flash memory has been updated to the latest 112-layer 3D TLC from Toshiba. This gives WD the rare capability of manufacturing all components on the SSD in-house, which not only helps with cost, but also makes them more independent from various supply-chain issues. What's not changed is that the SN770 is a 4-channel design, which of course limits the maximum transfer rates compared to an 8-channel design like the SN850, but this is mitigated by the more modern 112-layer flash (vs. 96-layer on the SN850). Also, and as expected, a DRAM cache chip is not included in the SN770 for cost reasons. Higher-end drives have a separate DRAM cache chip that stores a copy of the mapping tables of the SSD. This table helps the controller figure out where a piece of data is located; like most DRAM-less SSDs, the SN770 does use 64 MB of the host system's memory, though.