Toshiba Enterprise Performance HDD AL14SXB90EN 900GB Internal 2. 5\" SAS 12Gb/s 15000 rpm 128 MB Buffer The 12. 0 Gbit/s SAS interface AL14SX Series Enterprise Performance HDDs are Toshiba s highest-performing 15, 000rpm model line. Engineered for mission critical IT operations, an array of models are available with 512 native (512n), or emulated 512 (512e) or 4K native sector length technologies for optimum application and operating system compatibility. Toshiba s Persistent Write Cache technology protects against data loss in the event of unexpected power loss, and helps maintain optimum data reliability for high-duty cycle Mission Critical environments.