Contents hide 1 What are PMR and SMR hard disk drives? 1.1 Perpendicular Magnetic Recording (PMR) 1.2 Shingled Magnetic Recording (SMR) 1.3 Differences between PMR and SMR Your story on WD using SMR in some drives without mentioning it on the spec sheets was eye opening. The WD representative’s wording about the suitability of SMR … Continue reading How to tell a difference between DM-SMR and non-SMR (CMR) drives (HDD) – compare