Samsung 860 QVO 2TB SSD review - Specifications & Features

Samsung SSD 860 QVO Specifications

Samsung is to offer several versions of the 860 EQO which includes a 1 TB, 2 TB, and a 4 TB model. The sample that has arrived in our test lab is the 2 TB version of the drive. The 860 QVO series will come fitted with Samsung 4-bit, multi-level-cell (MLC) three-dimensional (3D) NAND flash memory from their latest 64-layer V-Nand node. Despite the SATA interface bandwidth limitations, the 860 QVO delivers sequential read (550 MB/s) and write (520 MB/s) performances(sequential). These upgrades are accompanied by enhanced random access performance for Client PCs. The 860 WVO promises to deliver improved endurance up to 1,200 TB of Total Bytes Written for the largest SSD (half that of the EVO models). It comes with a 3-year limited warranty. The MJX controller and multiple form factors allow much wider compatibility with devices. The 860 QVO fully supports Linux without issues. 

So V-NAND is used; 3D NAND is physical vertical NAND cell stacking not to be confused with chip stacking in a multi-chip package. In 3D NAND, NAND layers, not chips, are stacked in a single IC. The use of 4-bit-per-cell V-NAND simply raises the efficiency of memory production. Compared to 3-bit planar (or single layer) NAND flash, the 4-bit V-NAND has more than quadruple wafer productivity in Samsung's factories. The good news here is continued cost reduction and more capacity per NAND chip. Also, installed NAND toolsets in the wafer fabs can, for the most part, be reused, thereby extending the useful life of fab equipment. 

• Type: Solid State Drive
• Type: 2.5" 7 mm (Ultraslim) Form Factor
• Type: 860 QVO Series
• Sequential Read Speed: Up to 550 MB/s
• Sequential Write Speed: Up to 520 MB/s
• Random Read Speed Up to 97K IOPS
• Random Write Speed Up to 89K IOPS
• Warranty: 3 Years

Controller architecture

The 860 QVO has been equipped with Samsung's latest revisions controllers, a Samsung MJX controller. Realistically, all revision controllers are nearly similar, based on an ARM-based controller that of course is SATA 6 Gb/s compatible and can be paired with the latest NAND flash memory. Samsung mentioned in some tech white-papers that the EVO's latest MGX, MHX and now MJX controllers are able to get you superior multi-tasking results under heavy I/O loads and provide steadier performance on more tasks. The controller would be based upon an ARM Cortex R4 processor. If Samsung still follows the same design, it would have three cores that can execute multiple instructions at once, allowing, for example, one to be used for reading data, one for writing data and another for optimization. And that fact all by itself makes Samsung's claim on superior multi-tasking a very likely one.

There is a DRAM buffer in a bit of a 10:1 fashion, the 1TB SSD will see 1 GB of DRAM, the 4 TB version thus 4 GB. The DRAM is used for page table only lack of page table means it has to read and write the page table directly from NAND, as more data is saved onto the drive the longer writes may take as it has to update the page table between the NAND and the CPU on the SSD. Next, to that there is a bit of provisioning going on with an SLC cache, it's big on all models and up-to roughly 42 GB for the 1 TB model and 78 GB of sustained continuous writes for the 2 and 4 TB models, you will not see a TLC/QLC gap. Once you do pass that value, the SLC cache dries up (it switches to Direct to QLC/TLC writing) and that would result in low writes in the 100 MB/sec ranges. Leave the SSD alone in idle for a few minutes it will have emptied the SLC cache to the QLC/TLC) and your perf is back.

Pricing

Making your own SSD with your own controller, own PCB, own cache chips, and own NAND flash memory does have advantages as Samsung is able to keep the prices very competitive as this product is made 99% in-house.

• 4TB - ($599 expected - TBA)
• 2TB - ($299 expected - TBA)
• 1TB - $149 / £136.99

Prices are closing in on HDD values, 250 USD for a 2 TB model. So that's roughly 15 cents per GB and perhaps even lower as these are suggested retail prices, not street prices. Though, it needs to be lower in our opinion.