Western Digital WD Blue SN580

The NVMe solid-state drive (SSD) WD Blue SN580 is a consumer drive manufactured by Western Digital. Announced in June, 2023, the SN580 is the fourth generation of WD's Blue NVMe SSD product line, succeeding the SN570, SN550, and SN500. It is the first in the WD Blue line to utilize the PCIe 4.0 interface but is still positioned as a budget-oriented storage solution for cost-conscious consumers and OEM system builders.

With a launch MSRP of $49.99 for the 1TB model, the drive significantly undercuts many competing PCIe 4.0 SSDs. The SN580 competes mainly with other DRAM-less PCIe 4.0 drives in the same performance range, like the Kingston NV2 and Crucial P3 Plus.

Technical Specifications

Official datasheet

Controller

The SN580 uses a proprietary SanDisk-branded controller (model 20-82-10082), also known as Polaris MP16+, which is a four-channel DRAM-less design similar to controllers found in other WD NVMe SSDs including the Green SN350, Blue SN570, and Black SN770. Compared to the SN770, the controller operates at a lower bus rate to differentiate the product lines. Having no dedicated on-board DRAM, the controller utilizes Host Memory Buffer (HMB) technology with a 200MB allocation (more than the typical 64MB used by most DRAM-less SSDs).

Cache Architecture

As the first model in the Blue product line, the SN580 features Western Digital's nCache 4.0 technology, which was first introduced with the WD Black SN850. This is a departure from the static cache design of earlier Blue models, as the pseudo-SLC cache is dynamically sized and exceptionally large: testing reveals approximately 341GB of SLC cache for the 1TB model, meaning the drive can access a significant part of its entire capacity in SLC mode for burst writes. This can be compared to the the SN570's 12GB static cache.

NAND Type & Specifications

One area that remains unchanged from the predecessor is the 112-layer BiCS5 3D TLC NAND flash memory, the same generation used in the SN570 and SN770. For the 2TB model, the drive notably employs 1Tb (128GB) dies to achieve the capacity with minimal chip count, maintaining the single-sided design across all capacities.

Power Consumption

The SN580 is marketed as a low-power solution suitable for laptop applications, with specifications claiming:

• Average Active Power: 65mW
• Sleep State (PS5): 3.3mW

In real-world testing, the drives exhibits improved performance-per-watt efficiency. Thanks to lower heat generation during operation, thermal throttling will rarely occur during typical usage scenarios.