WD20EZRX-00D8PB0 Head Matching

[lcoughey]

I just received 4 brand new 2TB Western Digital Green drives that look identical, with a few minor exceptions:

Model Date DCM # of heads head map
WD20EZRX-00D8PB0 26-Jun-15 HHRNHTJCAB 6 1,2,3,4,5
WD20EZRX-00D8PB0 26-Jun-15 HHRNHTJCAB 6 0,2,3,4,5
WD20EZRX-00D8PB0 26-Jun-15 HHRNHTJCHB 4 0,1,4,5
WD20EZRX-00D8PB0 25-Jun-15 HARNHTJCAB 6 0,2,3,4

The only conclusion I have, right now is that the 2nd to last digit in the DCM suggests the number of physical heads or platters inside the drive.

ie, A = 6 physical heads or 3 platters, H = 4 physical heads or 2 platters

[Jared]

Very interesting... I usually never pay that much mind to the first/last couple digits of the DCM code. Are you sure the drives are all new, and not refurbished or re-manufactured?