Which drive did I buy?

Last night I bought a WD Green 2TB at Best Buy.  On the box it says the model number is WDBAAY0020HNC-NRSN, but the WD Data Lifeguard Diagnostics program says it’s a WDC WD20 EARS-00MVWBO.  I’m just curious which drive it is so I can view the specs.  I want to know if it has 32MB or 64MB cache and what the RPM is of the drive.

WDBAAY0020HNC is probably just the product number for the complete retail package. The actual model number is on the drive’s label and would be correctly reported by DLG.

This is replacing two WD 500GB Caviar 16 drives that I bought just over 3 years ago.  It will be used for backup only.  I use a 300GB 10K RPM Velociraptor for my boot drive with Windows 7 Ultimate x64.

So, is this 32mb or 64mb cache?

You can infer the specs of the WD20EARS from its model number.

WD Model Numbers - WD Internal Drives:

Your drive is a 3.5" (E), Desktop Caviar (A), 5400 RPM, 64MB cache ®, SATA 3Gbps (S).

There is also the following document.

WD Caviar Green Series Disti Spec Sheet:


Thanks, that was very helpful.