The new Samsung 870 QVO has 1, 2, 4, and 8TB models raising the capacity bar for a 2.5” internal SSD. To get there, it uses Samsung’s new 3D, 92-layer, 4-bit QLC (quad-level cell technology) V-NAND.
To get techy, the Samsung 870 QVO can store 4-bits of data across 15 different threshold voltages, and 3D memory is stacked on top of itself to save space. QLC is a little slower than earlier types of 3D V-NAND. QLC is the next step to narrow the gap in price between SSD and spinning hard disks.
There are some arguments that QLC is slower and less reliable than Multi-Level Cell (MLC), but the doubters said that about MLC when TLC was the go. Suffice to say that Samsung offers a three-year warranty, and large DRAM and SLC caches so that is not an issue.
SATA 6 means 6Gbps which sounds high but is really 750MBps in a half-duplex mode (one way at a time) mode. The interface maxes out at around 500MBps sequential read/write. Samsung says the 870 QVO offers best-in-class sequential read/write speeds of up to 560/530MBps. That is all you can get from SATA6.
To achieve that the 870QVO has 1TB/1GB, 2TB/2GB, 4TB/4GB and 8TB/8GB of high-speed LPDDR4 SDRAM as a cache. It is a Samsung MKX Controller can also dynamically allocate QLC V-NAND as extra SLC cache. In this case 1TB/42GB, 2TB/78GB, 4TB/78GBN and 8TB/78GB. So as long as the DRAM and SLC cache do not overflow these have great internal performance.
The warranty is nominally three years or Terabytes written. This is 1TB/360, 2TB/720TB, 4TB/1440TB and 8TB/2880TB.
GadgetGuy has not yet tested these as they are coming between July and September. But we have read a few early reviews of the 1TB model. Tests indicate that its similar in speed to its predecessor the 860 QVO, so the advice is that unless you need 8TB then a 1, 2, or 4TB 860 QVO using TLC V-NAND is just as good and probably less costly.