Flash memory prices have been on a downward trajectory for years. A decade ago, this trend was helping SSDs establish a foothold in the consumer market—largely for enthusiasts. Now, SSDs have taken over as the default storage medium for consumer PCs and further advances in flash memory are no longer pushing consumer SSDs into new product segments. Instead, cheaper flash is driving an increase in SSD capacity.
That growth in drive capacity has not been steady. For both technical and marketing reasons, consumer SSD capacities stick close to powers of two. The first 2TB consumer SSDs started to show up in 2015, and now 2TB options are common across all the SSD market segments. 4TB drives started to show up in 2018 but are still quite rare, and this year we've seen the first 8TB consumer SSDs.
Today we're looking at the first two consumer-oriented 8TB SSDs. The 8TB Samsung 870 QVO is a SATA drive from the brand that has been at the forefront of the past several capacity increases and leads the SSD market by most other measures. The other drive is the 8TB Sabrent Rocket Q, a M.2 NVMe drive from a brand that's working to stand out from the crowd of many other Phison partners. Unsurprisingly, both of these drives use four bit per cell QLC NAND flash memory which offers the lowest cost per GB and the highest per-die capacities currently available. QLC NAND generally puts SSDs into an entry-level market segment, but due to their extreme capacities these 8TB SSDs are still some of the most expensive drives in the consumer SSD market.
The Rocket Q does cut corners a bit by using just one fourth of the DRAM we usually see on mainstream SSDs. That hurts a bit at the lower capacities (though nowhere near as much as a fully DRAMless design would), but is much less of a problem for this 8TB model: 2GB of DRAM is still plenty for the SSD to handle any typical consumer workload.
The Rocket Q lineup goes from 500GB to 8TB, but we generally consider QLC drives smaller than 1TB to be a poor alternative to DRAMless TLC drives. That's even more true for the Rocket Q, because the 500GB model can only use half of the Phison E12's 8 channels.
Sabrent has also introduced the Rocket Q4 as a partial successor. This uses the Phison E16 controller and brings PCIe 4 support and improved performance. However, the E16 is not yet (and may never be) available in a small package size like the E12S controller, so it is not yet practical for Sabrent and Phison to squeeze 8TB of QLC onto a PCIe gen4 M.2 drive.