In this paper, an internal model control (IMC) based proportional integral (PI) controller is designed for DC servomotor using the concept of model order reduction. The beauty of the presented approach is that the optimal performance can be achieved by lower-order controller, hence reduces the size of the controller. Moreover, there is no need for extra filter which is generally augmented with IMC-PID controller. Particularly here, it is shown that without using additional filter, the performance of IMC-PI controller is better in comparison to IMC-PID controller with additional filter. The proposed methodology has been validated on an experimental set up of precision modular servo (PMS) system using its different reduced-order models. Further, it is shown that the reduced model based on Routh array is the best suited for obtaining optimal performance for speed control of PMS system.