Western Digital on Thursday (23/04) released an updated statement about the company's stand on SMR (shingled magnetic recording) being used on certain internal hard drives, including certain client-segment WD Red models recommended by the company for NAS applications, without proper disclosure on the product's marketing materials or data-sheets. It's surprising to note that SMR is being used not in some of the higher-capacity models (8 TB or higher) as previously thought, but rather lower-capacity ones, 6 TB or lower, including a 2 TB 3.5-inch drive, and a 1 TB 2.5-incher.

Perhaps SMR is being used in these lower-capacity drives to reduce the number of platters, by cramming in more data per recording surface. As on 22nd April (when the list was internally compiled by Western Digital), there are 9 client-segment hard drives that use SMR, four of which are from the company's WD Red family, two each from the WD Blue 3.5-inch and WD Blue 2.5-inch families; and one from the 2.5-inch WD Black family. Among the WD Red series drives with SMR are the 2 TB WD20EFAX, the 3 TB WD30EFAX, the 4 TB WD40EFAX, and the 6 TB WD60EFAX.