Western Digital 250GB Internal Solid State Drive (WDS250G2B0A) The WD Blue 3D NAND SATA SSD utilizes 3D NAND technology for capacities up to 2TB with enhanced reliability. Featuring an active power draw up to 25% lower than previous generations of WD Blue SSDs, you’re able to work longer before recharging your laptop, while sequential read speeds up to 560MB/s and sequential write speeds up to 530MB/s give the speed you want for your most demanding computing applications. Combined with the free, downloadable WD SSD Dashboard software, you can confidently upgrade your system to the WD Blue 3D NAND SATA SSD. As used for storage capacity, one terabyte (TB) = one trillion bytes. Total accessible capacity varies depending on operating environment. Active power draws are up to 25% lower during sequential reads than previous generations of WD Blue SSD at the 500GB capacity point. As used for transfer rate or interface, megabyte per second (MB/s) = one million bytes per second and gigabit per second (Gb/s) = one billion bits per second. MTTF = Mean Time To Failure based on internal testing using Telcordia stress part testing. TBW (terabytes written) values calculated using JEDEC client workload (JESD219) and vary by product capacity.