What is the reason that using preemptive multitasking leads to increased resource consumption?

Preemptive multitasking requires the operating system to regularly switch contexts between tasks (processes or threads). This leads to additional resource costs for several reasons:

• Context switch: Saving and loading the state of the processor, registers, and memory is an expensive operation.
• Cache memory: When switching tasks, the processor cache may be cleared, reducing efficiency.
• Synchronization: Frequent switching can cause locks and waits, increasing overhead.

Thus, the more often task switching occurs, the more resources are spent managing them rather than performing useful work.