QLC Goes To 8TB: Samsung 870 QVO and Sabrent Rocket Q 8TB SSDs Reviewed

Conclusion

The sheer capacity alone is enough to make the 8TB Sabrent Rocket Q and 8TB Samsung 870 QVO impressive and groundbreaking products. But reaching this new capacity point for consumer SSDs has required significant tradeoffs. These two drives rely on QLC NAND flash memory with worse performance and write endurance than the TLC NAND used by mainstream consumer SSDs. Thankfully, the sheer high capacity of these drives offsets some of the downsides of QLC NAND, but it does not eliminate all of them.

The result is a pair of drives that blur the lines between low-end and premium products. The price tags are unquestionably premium territory, and even on a per-GB basis these drives aren't the cheapest. Rather than offering economies of scale, the niche status of such high-capacity SSDs carries a bit of a price premium. This is especially true of the 8TB Sabrent Rocket Q: it is currently at its cheapest-ever price, but is still 45% more expensive than the 8TB Samsung 870 QVO. The Rocket Q's use of an NVMe controller (rather than a SATA controller) only accounts for a few dollars of this vast difference. Sabrent is probably paying more to buy Micron's QLC on the open market than it costs Samsung to use their own QLC, but a large portion of this price disparity can simply be blamed on lack of competition. The Sabrent Rocket Q was the first 8TB consumer NVMe SSD, and only one competitor has showed up since: the Corsair MP400, based on the same basic formula as the Rocket Q.

While its price tag certainly appears exorbitant next to the cheaper Samsung 870 QVO, there's no question that the 8TB Rocket Q deserves more premium pricing. The Samsung 870 QVO is slow even by SATA SSD standards, and is best used as a secondary drive for bulk data with low performance requirements. Ignoring the price, it looks great in comparison to an 8TB hard drive: silent, faster (usually), more compact. But compared against other SSDs it is lackluster. The fact that it's no faster than the 2TB and 4TB models is another disappointment, and a clear sign that 8TB is far beyond the sweet spot of the SSD market.

The Rocket Q on the other hand is fast enough to provide a good experience as a primary drive, even if it gets loaded down with several TB of data. It won't always match the performance of a smaller high-end drive, but it doesn't suffer as much from the worst-case performance problems that plague most QLC SSDs (and likely the smaller capacities of the Rocket Q as well). At its worst, the Rocket Q only degrades down to a bit slower than mainstream SATA drives. Rocket Q doesn't quite manage to provide that magical combination of maximum capacity and maximum performance, but comes surprisingly close.

Looking at the overall state of pricing in the SSD market, among NVMe drives, the current 8TB options are the Sabrent Rocket Q and the Corsair MP400, which use almost identical hardware. The Sabrent Rocket Q currently has better pricing than the more recently-released MP400. Dropping down to less extreme capacities, neither product is the best option. Microcenter's Inland Platinum is their version of the Phison E12 with QLC, and it's cheaper than the Rocket Q at 1TB, 2TB and 4TB. There's also the ADATA XPG SX8100, by far the cheapest multi-TB NVMe SSD with TLC NAND. It uses Realtek's RTS5762 controller so it's really not a high-end drive even by PCIe 3 standards, but it's definitely a step up from the QLC drives, especially for heavier workloads. The 4TB SX8100 is currently $499 and was recently on sale for $399.

In the consumer SATA SSD market, there are far fewer options for very large drives. The 870 QVO is unopposed at the 8TB capacity, and the only 4TB alternatives are TLC drives. However, the 4TB WD Blue at 20% more than the 4TB 870 QVO seems like a pretty good upgrade. At 1TB and 2TB the 870 QVO is uncompetitive: the 860 EVO is currently only $10 more at 1TB, and the same price at 2TB.

Looking Forward

For most consumers, 8TB SSDs will not become a realistic proposition for several more generations of 3D NAND technology. These drives are an early preview of that future, and highlight what else needs to improve aside from just the price. Even though QLC NAND has a reputation for poor performance, both of these 8TB drives are often bottlenecked instead by the controller: partly a result of putting 64 NAND flash dies behind 8 channel controllers. The consumer SSD market is unlikely to reverse direction and start moving towards wider controllers, so in order for 8TB drives to go mainstream without the limitations of today's models, we'll need to see higher per-die capacities and much higher IO speeds per channel.

Higher die capacities will go hand in hand with cost reductions in future generations of 3D NAND flash memory, and by the time 8TB drives are mainstream we'll probably see 1TB drives as the same kind of baseline that 256GB drives are today. Movement toward higher interface speeds between the NAND and controller is already underway, spurred on by the arrival of PCIe 4.0. There's now demand for 4-channel NVMe SSD controllers capable of several GB/s, which requires NAND interface speeds far in excess of what the Sabrent Rocket Q's Phison E12 is capable of.

We will soon be continuing our exploration of newer QLC SSDs with a look at the 1TB Corsair MP400, which should be very similar to the 1TB Rocket Q. At lower capacities, the limitations of QLC NAND are a bigger challenge, and there's more competition from entry-level TLC drives. We're also testing the Sabrent Rocket Q4, the PCIe 4.0 successor to the Rocket Q—another hybrid of high-end and low-end features. However, this one currently only goes up to 4TB.