The zigzag magnetic transition due to the magnetic clusters has been found to enlarge the differential pulse width (dPW50). In order to simulate the resolution or dPW50 precisely with magnetic cluster effect, a micro-track model was employed in the manner that local transition positions were determined by magnetic clusters. The magnetic cluster size was set to be the average diameter of the circles, which fit the magnetic clusters on MFM images in shape. Simulated transition jitter based on the distribution of the center position of circles is compared with experimentally measured value by time domain analysis of readout waveform. The calculated resolution of the transition model with magnetic cluster was successfully validated by the measured resolution along with the jitter with reasonable accuracy. (C) 2004 Elsevier B.V. All rights reserved.