Abstract: A motor control processor controls motor spin-up in a disk drive by detecting environmental temperature at the spindle motor of the disk drive, controlling commutation phase advance to generate substantially maximum torque if the detected environmental temperature indicates that maximum torque is needed, and adjusts the commutation phase advance for optimal efficiency after the maximum torque is no longer needed. Following motor start and reaching operational speed, the motor is operated in a steady-state maximum operating efficiency mode unless sensed environmental temperature indicates that maximum torque, rather than maximum efficiency, is needed. The system determines that the need for maximum torque has passed either when a predetermined time interval after motor start expires or by repeatedly polling motor temperature information.