Shingle magnetic recording assessment with spinstand measurement

Shingle Magnetic Recording (SMR) is a candidate to realize recording density of over 1 Tbit/in². At the cost of complex HDD firmware, we can expect many gains such as higher write-ability to break through the famous tri-lemma. In this paper, promising empirical data and concerns found on spinstand were introduced and discussed. More than 18 dB of better reverse overwrite (ROW) than conventional write recording (CWR) was confirmed at 40 nm of track pitch. Areal density capability (ADC) was improved by 25.5% by SMR. Another gain from SMR was observed at inner diameter (ID) and outer diameter (OD) that ADC loss due to skew effect was improved by using preferable side write pole edge. The dependence of ADC on magnetic read width measured with micro-track method (MRWu) indicates that side reading is limiting ADC. Reduction in side reading through narrower MRWu and inter-track interference cancellation technology are necessary to further improve ADC. BPI capability improvement by steeper down track field gradient at the track edge needs to be considered.