Lenovo ThinkSystem 2.5" 2.5" PM883 240GB EN SATA Hot Swap SSD
SKU# AC29012, Model# 4XB7A10195

The Entry SATA SSDs have the following features:

• Low cost, read-intensive SSD from Samsung
• 2.5-inch or 3.5-inch industry standard form factor with hot-swap tray
• 6 Gbps SATA interface
• Advanced ECC Engine and End-to-End Data Protection
• Samsung 32 layer V-NAND stacks the vertical NAND layers in three dimensions, solving the cell-to-cell interference that causes data corruption in planar NAND.
• Protect data integrity from unexpected power loss with Samsung's advanced power-loss protection architecture
• Supports Self-Monitoring, Analysis and Reporting Technology (S.M.A.R.T).

• Dynamic Thermal Guard Protection protects the SSD from overheating by automatically controlling the speed of the CPU relative to its core temperature

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

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

Because of such behavior by Entry solid-state drives, careful planning must be done to use them only in read-intensive or mixed up to 70% read/30% write environments to ensure that the TBW of the drive will not be exceeded before the required life expectancy.

For example, the 480 GB PM883 Entry drive has an endurance of 683 TB of total bytes written (TBW). This means that for full operation over five years, write workload must be limited to no more than 374 GB of writes per day, which is equivalent to 0.8 full drive writes per day (DWPD). For the device to last three years, the drive write workload must be limited to no more than 624 GB of writes per day, which is equivalent to 1.3 full drive writes per day.