The ADATA Legend 850 is a solid-state drive in the M.2 2280 form factor, launched in 2023. It is available in capacities ranging from 512 GB to 2 TB. This page reports specifications for the 1 TB variant. With the rest of the system, the ADATA Legend 850 interfaces using a PCI-Express 4.0 x4 connection. The SSD controller is the SM2269XT from Silicon Motion, a DRAM cache is not available. ADATA has installed 176-layer TLC NAND flash on the Legend 850, the flash chips are made by Micron. Please note that this SSD is sold in multiple variants with different NAND flash or controller, which could affect performance, the "Notes" section at the end of this page has more info. To improve write speeds, a pseudo-SLC cache is used, so bursts of incoming writes are soaked up more quickly. The cache is sized at 300 GB, once it is full, writes complete at 1800 MB/s. Copying data out of the SLC cache (folding) completes at 880 MB/s. Thanks to support for the fast PCI-Express 4.0 interface, performance is excellent. The Legend 850 is rated for sequential read speeds of up to 5,000 MB/s and 4,500 MB/s write; random IOPS reach up to 400K for reads and 550K for writes.
At its launch, the SSD was priced at 80 USD. The warranty length is set to four yearsADATA guarantees an endurance rating of 1000 TBW, a good value.