Lenovo 7XB7A05925 internal solid state drive 1.6 TB Half-Height/Half-Length (HH/HL) PCI Express 3.0 NVMe MLC

The Lenovo PX04PMC NVMe Performance Flash Adapters in capacities of 1.6 TB and 3.2 TB are advanced data center PCIe Flash Storage Adapters optimized for write-intensive performance, endurance, and strong data protection for ThinkSystem servers. They are engineered for high performance and endurance in a cost-effective design, and to support a broader set of workloads.

Non-Volatile Memory Express (NVMe) is new PCIe 3.0 high performance solid-state storage technology that provides high I/O throughput and low latency. NVMe interfaces remove SAS/SATA bottlenecks and unleash all of the capabilities of contemporary NAND flash memory. Each Flash Storage Adapter has direct PCIe 3.0 x4 connection, which provides at least 2x greater bandwidth and 2x lower latency than SATA/SAS-based SSD solutions. NVMe Flash Storage Adapters are also optimized for heavy multi-threaded workloads by using internal parallelism and many other improvements, such as larger I/O queues.

The Lenovo NVMe Performance Flash Adapters have the following features:

- Half-high half-length PCIe adapter with PCIe 3.0 x4 host interface
- Based on the Toshiba PX04P Add-in Card (AIC), PX04PMCxxx
- 19nm MLC NAND (128 Gb/die)
- 10 drive-write-per-day (DWPD) endurance for write-intensive workloads
- Full Power-Loss-Protection and End-to-End Data Protection
- Low power consumption (maximum 18.5 W)

Enterprise Performance Flash Adapters and Enterprise Mainstream Flash Adapters have similar read IOPS performance, but the key difference between them is their endurance (or lifetime) (that is, how long they can perform write operations because Flash Adapters (like SSDs) have a finite number of program/erase (P/E) cycles). Enterprise Performance Flash Adapters have higher endurance compared to Enterprise Mainstream Flash Adapters. Write endurance is typically measured by the number of program/erase (P/E) cycles that the adapter incurs over its lifetime, listed as the total bytes of written data (TBW) in the device specification.

The TBW value assigned to a Flash Adapter is the total bytes of written data (based on the number of P/E cycles) that an adapter can be guaranteed to complete (% of remaining P/E cycles = % of remaining TBW). Reaching this limit does not cause the adapter to immediately fail. It simply denotes the maximum number of writes that can be guaranteed. A Flash Adapter will not fail upon reaching the specified TBW. At some point based on manufacturing variance margin, after surpassing the TBW value, the adapter will reach the end-of-life point, at which the adapter will go into a read-only mode.

Even though Enterprise Performance Flash Adapters have high endurance, careful planning must still be done to ensure that the total amount of data expected to be written to the drive over its life will not exceed the stated total bytes written (TBW) property of the drive.

For example, the 1.6 TB adapter has an endurance of 29,200 TB of total bytes written (TBW). This means that for full operation over five years, write workload must be limited to no more than 16 TB of writes per day, which is equivalent to 10.0 full "drive" writes per day (DWPD). For the device to last three years, the write workload must be limited to no more than 26,667 GB of writes per day, which is equivalent to 16.7 full drive writes per day.