Review on Dell/Seagate Constellation ES ST4000NM0033 4TB 7200RPM 128MB Cache SATA 6.0Gb/s Internal Enterprise Hard Drive – 5 Year Warranty: Reliable Storage Solution for Robust Business Applications by Heidi Garcia

25% of these drives failed within two weeks. The "smartctl" tool in Linux shows that each drive has been powered on for 5 years at a time. Definitely NOT what I expected based on the text description used by the vendor. These discs have been used for a long time. I couldn't find any indication on the Revain product page that these are used discs, even after looking at them several times after some of them stopped working. I'm taking my time to write this review because it took me about 10 hours to recover my data and that's because I had a failover RAID using the drives I bought here. If someone is planning to buy just one of these, by no means do so as irretrievable data loss may result.