What is the primary factor that affects the performance of Round Robin…

In Round Robin (RR) CPU scheduling, the time quantum is the fixed amount of time a process is allowed to run before being preempted and placed back at the end of the ready queue.

Choosing the right time quantum size is a delicate balancing act that directly dictates the efficiency and responsiveness of the operating system:

• If the Time Quantum is too large: The algorithm behaves exactly like First-Come, First-Served (FCFS). Processes with long CPU bursts will hold onto the processor for their entire duration, causing shorter, interactive processes to experience high waiting times.

• If the Time Quantum is too small: The CPU will switch between tasks incredibly quickly. While this provides excellent responsiveness (giving the illusion that all programs are running simultaneously), it triggers a massive amount of context switches. Since saving and loading process states takes CPU cycles, a tiny time quantum forces the system to waste most of its processing power on scheduling overhead rather than actual user programs.