Samsung 860 QVO

Released in November 2018, Samsung's 860 QVO was the manufacturer's first consumer drive to use QLC (4 bits per cell) V-NAND. It arrived in the same period as the Intel 660p, the first mainstream QLC NVMe drive. Samsung entered QLC in the SATA space, starting at 1TB and going up to 4TB.

QLC NAND stores four bits per cell rather than three, which reduces cost per gigabyte at the expense of write endurance and sustained write speed. Samsung addresses the write speed issue with Intelligent TurboWrite: a large SLC write buffer (up to 78GB on the 1TB model, higher on larger capacities) that absorbs sequential writes at close to MLC speeds. Writes that exceed the buffer fall back to native QLC speeds, which are much lower.

The drive uses the same MJX controller as the 860 EVO and 860 PRO. Its sequential speeds — 550 MB/s read, 520 MB/s write — match the EVO and are measured within the SLC buffer. The 860 QVO offered a more consumer-friendly cost per gigabyte than the EVO: it reached 4TB in 2.5" form when the EVO topped out at 4TB as well, but at a lower cost.

The warranty is 3 years, shorter than the 5-year coverage on the EVO line. Similarly, TBW ratings are lower for the QVO compared to the EVO at 360 TBW for the 1TB versus 600 TBW for the EVO 1TB. This is rarely an issue in consumer PCs but a problem for storage-intensive, professional use cases.