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

Mixed Random Performance

Our test of mixed random reads and writes covers mixes varying from pure reads to pure writes at 10% increments. Each mix is tested for up to 1 minute or 32GB of data transferred. The test is conducted with a queue depth of 4, and is limited to a 64GB span of the drive. In between each mix, the drive is given idle time of up to one minute so that the overall duty cycle is 50%.

The 8TB Sabrent Rocket Q's performance on the mixed random IO test is much better than any of the other low-end NVMe drives; the DRAMless TLC drives are the slowest in this bunch, and the Intel 660p with its four-channel controller cannot keep up with the Rocket Q's 8-channel Phison E12. The 8TB Samsung 870 QVO is slower than most of the other SATA drives in this bunch, but still has a clear advantage over the 1TB model.

Power Efficiency in MB/s/W	Average Power in W

The high-end consumer NVMe drives and the Samsung 860 EVO TLC SATA drive top the power efficiency chart for the mixed random IO test. The Sabrent Rocket Q's efficiency is a significant step down from there, but still a bit better than any of the other low-end drives. The 8TB 870 QVO's efficiency score is worse than the 4TB model's, but clearly better than the 1TB model or either of the DRAMless TLC NVMe drives.

Sabrent Rocket Q 8TBSamsung 870 QVO 8TBSamsung 870 QVO 4TBSamsung 870 QVO 1TBSamsung 860 DCT 3.84TBKingston DC450R 3.84TBIntel P4510 8TBSK hynix PE6011 7.68TBIntel SSD 660p 1TBSamsung 860 EVO 4TBSamsung 970 EVO Plus 2TBToshiba BG4 1TBHP EX950 2TBMushkin Helix 1TB

Both of the 8TB QLC drives show fairly typical performance curves for the mixed random IO test: little or no performance drop when writes are first added to the mix, and then increasing performance that accelerates toward the end of the test as write caching becomes more effective. The 8TB 870 QVO doesn't show the signs of a filled SLC cache that we see from the 1TB model, and neither 8TB QLC drive shows the nearly-flat performance exhibited by the two DRAMless TLC drives.

Mixed Sequential Performance

Our test of mixed sequential reads and writes differs from the mixed random I/O test by performing 128kB sequential accesses rather than 4kB accesses at random locations, and the sequential test is conducted at queue depth 1. The range of mixes tested is the same, and the timing and limits on data transfers are also the same as above.

The Sabrent Rocket Q's performance on the mixed sequential IO test is competitive with the high-end consumer TLC drives, and far better than the other low-end NVMe options. The 8TB Samsung 870 QVO has distinctly lower performance than the smaller capacities, but isn't quite the worst overall performer.

Power Efficiency in MB/s/W	Average Power in W

The good performance of the Rocket Q on the mixed sequential IO test comes at the cost of worse power efficiency than the DRAMless TLC competition, but its efficiency scores are still decent. The 8TB 870 QVO's efficiency scores are worse than any of the other consumer SSDs in this bunch.

Sabrent Rocket Q 8TBSamsung 870 QVO 8TBSamsung 870 QVO 4TBSamsung 870 QVO 1TBSamsung 860 DCT 3.84TBKingston DC450R 3.84TBIntel P4510 8TBSK hynix PE6011 7.68TBIntel SSD 660p 1TBSamsung 860 EVO 4TBSamsung 970 EVO Plus 2TBToshiba BG4 1TBHP EX950 2TBMushkin Helix 1TB

As with several other synthetic tests in our suite, the mixed sequential IO test has the Sabrent Rocket Q showing rather variable performance, though fortunately without any severe drops. It performs a bit better during the more write-heavy half of the test.

The Samsung 870 QVO shows relatively flat and consistent performance throughout this test, but as is common for Samsung drives there's a bit of a decreasing performance trend during the read-heavy half of the test.