Popular SSD vendor uses a clever trick to make slower, less durable flash components perform much better, but don’t expect miracles
Although QLC NAND can store significant amounts of data, its performance lags behind other NAND types. Because it is denser (with four bits per cell) than TLC (with room for three), it is generally slower and less robust.
Western Digital has taken a clever approach to improving the performance and durability of its new SN5000S QLC flash drive. Thanks to the integration of a fast pseudo-SLC cache, raw cell overprovisioning, and a controller that minimizes write amplification, it surpasses its TLC predecessor, SN740.
While the older SN740 was built using WD and Kioxia’s fifth-generation BiCS 112-layer vertically stacked 3D NAND, the newer SN5000S takes advantage of BiCS sixth-generation 162-layer NAND.
Speed improvements
Thanks to SLC caching, the SN5000S has shown a 1.4% increase in random read IOPS and a 12.5% improvement in random write IOPS. The sequential read and write operations are said to be faster by 16.5% and 15.5% respectively.
The SN5000S comes in M.2 2280 “gumstick” and M.2 2230 form factors with capacities ranging from 512 GB to 2 TB.
While the SN5000S has shown significant improvements, it’s worth noting that it consumes slightly more power than the SN740 at peak times. Peak power on the 2TB model is 6.9W, compared to 6.3W on its predecessor.
Additionally, the SN5000S 512GB and 1TB models have lower endurance than the SN740 equivalents. However, this improves with the 2TB model: the SN5000S reaches 600 TBW, while the SN740 is 500 TBW.
Since the SN5000S drives are primarily for OEMs, no official pricing is available.