WD HDDs with 2TB Each Platter

As the CAP and TPI are increasing quickly, pc users get hard drives of bigger and bigger capacity, each platter can hold much more than before.

WD20EFAX-xxFB5Nx 2TB, 1 platter 2 heads
WD30EFAX-xxJH4Nx 3TB, 2 platters 3 heads
WD40EFAX-xxJH4Nx 4TB , 2 platters 4 heads
WD40EMAZ-xxTKPBx 4TB, 2 platters 4 heads
WD60EMAZ-xxTKPBx 6TB, 3 platters 6 heads
WD60EFAX-xxSHWNx 6TB, 3 platters 6 heads