Samsung has started shipping the 860 QVO, a 4TB QLC consumer SSD.
QLC means quad-level cell flash and 4bits per cell – one more than the typical TLC (3bit/ cell) flash used in many SSDs today.
The downsides of higher capacity are slower read/write speeds and lower endurance than TLC. But drive controller and over-provisioning.can mitigate this.
The 2.5-inch form factor 860 QVO uses 32 x 1Tbit (128GB) 64-layer V-NAND dice and comes in 1, 2 and 4TB versions. It has a 6Gbit/s SATA interface.
The drive incorporates a Samsung MJX controller and employs a secondary SLC (1bit/cell – the fastest flash) cache (TurboWrite technology) to speed write performance; with the 1TB drive getting 42GB and the others 78GB of cache. Random read/write IOPS are up to 97,000 and 89,000 respectively, which is unexpectedly balanced. Typically, results skew to reads.
Sequential bandwidth is up to 550MB/sec for reads and 520MB/sec for writes. Random and sequential numbers are similar to Samsung’s TLC 860 EVO SSD but write speeds will drop if the stream of incoming data overwhelms the SLC cache.
There is a three-year warranty and the 4TB drive supports 1,440TB written (TBW), with the 2TB one supporting 720TBW and the 1TB version 360TBW. That means the 4TB drive supports roughly 1.3 drive writes per day (DWPD).
Samsung vs. Intel
Intel has dropped a pair of QLC SSDs on the market, the SSD 660p M.2 format consumer drive and the D5-P4320 data centre drive.
How does the Intel 660p, with its 512GB, 1TB and 2TB capacities, compare on speed with Samsung’s 860 QVO ? The short answer is – very well indeed.
That said, the drives are aimed at different markets. For instance, the 860 QVO can be used to replace a 2.5-inch disk drive: Intel’s 660p cannot. Intel’s 660p can accelerate a consumer desktop or laptop much better than the 860 QVO.
The Intel drive has an NVMe v1.3 PCIe 3 x 4 interface, which is much faster than the 860 QVO’s 6Gbit/s SATA. This enables it handle to up to 220,000 random read and write IOPS and 1,800 sequential read and write bandwidth.
The drive is warranted for five years and supports 0.1 DWPD.
The 860 QVO is available this month and costs $149 for 1TB, $299 for 2TB and $499 for 4TB. At time of writing, a 2TB Intel 660p costs $436.99 on Newegg.