Drives I RMA have actual bad sectors. You have a good batch. These drives tend to either last 10+ years, or fail in 1-3 years, and there is a clear bimodal dist

Drives I RMA have actual bad sectors. You have a good batch. These drives tend to either last 10+ years, or fail in 1-3 years, and there is a clear bimodal distribution. I think about half the drives in my array are original too.