SNR and Density Limit Estimates: A Comparison of Longitudinal and Perpendicular Recording

Simplified Neel-Arrhenius analysis is utilized to determine limiting densities versus SNR for longitudinal and keepered-perpendicular media. Dominant transition noise is assumed and the effects of grain size distribution and storage above room temperature are included. Perpendicular recording potentially exhibits a higher density than longitudinal; for example, at SNR = 20 dB, the limiting densities are approximately 500 and 100 Gbit/[in.sup.2], respectively. Index Terms--Density limits, longitudinal and perpendicular thin film media, magnetic recording, signal-to-noise ratio, thermal decay.