Most of the internet applications required high speed internet connectivity. Crosspoint Buffered Switches are widely used switching architectures and designing a scheduling algorithm is a major challenge. PQRS and D-PQRS are the two most successful schedulers used in Crosspoint Buffered Switches under unicast traffic. In this paper, we analysed the performance of PQRS and DPQRS algorithms by varying the crosspoint buffer size. Simulation result shows the delay performance of the switch increases if the size of the buffer increases.