Were they all firmware upgraded? I had a DOA and one firmware death in the first week of buying over a dozen. Since then all of the 7200.11's have been working fine on the Adaptec 31605 in raid 6. Just bought 8x WD 1.5 greens and another 8 hitachi drives (2x 1TB 6x 2TB) and the hitachi were all fine whilst the WD Greens saw 3/8 die in 14 days. I'm probably going to JBOD the greens for backup now and buy more Hitachi's.