Once again we stand on the precipice of a super cheap, super high-capacity SSD that will put the final nail in the coffin of HDDs inside gaming PCs. But is the Samsung 870 QVO 1TB the storage drive that will send us over the cliff? No, unfortunately not. But it is a little better than before.

The Samsung 870 QVO 1TB is aimed squarely at the PC-building budget segment, trying to deliver high capacity at a low price set at $130 (£111). With a SATA interface connection of up to 600 MB/s, the 870 QVO is more likely to find a new home as an expansion drive alongside faster NVMe boot drives than as a mainstay in new PCs.

Looking at the QVO's read/write performance, it will be difficult to discern what makes this particular drive so below the similar SATA-based Evo and Pro lines. But first appearances can be deceiving, and it is all in Samsung's choice of NAND flash technology.

You may be familiar with the variation in bits per cell as it relates to SSD performance, reliability, and capacity. This is a relatively simple concept. The highest performing and most reliable drives are built using single-level cells, or SLC for short. Each NAND cell is typically a set of two gates that can store a charge, meaning one of two values: 0 or 1. To read back the value of a cell, it must be checked to see if the charge meets a certain threshold value.

Increasing the number of bits per cell up to a quad-level cell (QLC), as seen in the 870 QVO (which Samsung calls a 4-bit MLC), requires increasing the number of potential threshold voltages that must be checked to evaluate a cell's value. As a result, checking a cell with a 4-bit value takes much longer than checking a cell with a 1-bit value. As a result, QLC drives (in this case, the 870 QVO 1TB) will see sequential write speeds drop to 80 MB/sec when QLC NAND flash is used, while the 860 Pro (2-bit MLC) SATA drive will maintain speeds in excess of 500 MB/sec. The 860 Pro (2-bit MLC) SATA drive, on the other hand, maintains speeds in excess of 500 MB/sec.

It is worth noting that the 1TB model is the slowest of the four available capacities when relegated to 80MB/sec QLC speeds; the 2TB, 4TB, and 8TB drives are all rated at 160MB/sec.

To work around this physical limitation to some extent, while maintaining the value-oriented structure of the QVO lineup, Samsung again employed some of the Turbowrite SLC NAND in the 870 QVO. in all 870 QVO capacities (up to 8TB models), pre-allocated The pre-allocated Turbowrite buffer is set to 6GB for all 870 QVO capacities (up to 8TB model). This provides 6GB of SLC capacity, which can increase performance to a rated speed of 530MB/sec for file transfers of the same size or smaller. For larger capacities, Intelligent Turbowrite adds another 36GB, for a total of 42GB for 1TB drives and 78GB total TurboWrite buffer for 2TB, 4TB, and 8TB drives.

The previous generation Samsung 860 QVO comes with the same loadout with a total 42GB TurboWrite capacity, but it was rated at 520MB/sec-10MB/sec from the 870 QVO's pace.

As for the impact on the performance of this drive, it should still be said that the SATA interface is a far more performance limiting factor than anything else.

Neither the ATTO nor the AS SSD tests demonstrated the lag of the QLC flash. Sequential read speeds remain around 530MB/s in both compressible and non-compressible benchmarks, a small margin from the advertised 560MB/s performance, enhanced by the 1GB of LPDDR4 DRAM cache memory on board. Sequential write speeds settle around 500 MB/sec, well above the 80 MB/sec of onboard flash.

PCMark 10's full 204GB storage test, which attempts to replicate real-world usage, showed the drive with an index score of 722, comparable to what one would expect from a SATA drive. Similarly, average access times and bandwidth, at 244μs and 121.32MB/s respectively, are not far behind what NVMe SSDs using PCIe 3.0 show, which is hardly a fair fight.

Realistically, the significant speed limitations of the SATA interface undermine the importance of 4-bit MLC (QLC) NAND in the Samsung 870 QVO 1TB. If you're looking for more capacity for a few games and can't afford an NVMe slot, this product will serve you just as well as any other.

A competing TLC drive that costs about the same as the Samsung 870 QVO 1TB and maintains at least some performance for the duration of its use is $130 (£111) (if a bit cheaper).

If you are buying a Samsung drive because you want the best SATA, with all due respect to the still relatively nascent technology, this is not one of those. And if you are not buying the Samsung brand for its renowned performance and reliability, what are you buying it for? Our cups are overflowing with excellent, low-cost SSDs right now.