WD RE 7200 RPM hard drives are engineered to thrive in a high duty cycle RAID system while still offering traditional low cost-per-capacity desktop value. Designed and manufactured to server-class standards, WD RE drives provide RAID-specific, time-limited error recovery (TLER) to significantly reduce drive fallout caused by extended drive error-recovery processes and are tested to 1 million hours MTBF. These drives include an 8 MB (SB) or 16 MB (YS) cache for faster time to data and fluid dynamic bearings (FDB) to reduce heat, vibration, and noise.