Would an algorithm that performs several independent calculations concurrently (e.g., matrix multiplication) be more efficient if it used threads, or if it did not use threads? Why is this a hard question to answer?

What will be an ideal response?

The answer to this question depends on the implementation of threads and if the system is a uniprocessor system or a multiprocessor system. If the system is a multiprocessor system, the function using threads might be more efficient if each thread could execute on a separate processor. However, if the system is a uniprocessor system with a user-level library, the function using threads would be less efficient due to the additional overhead incurred by spawning threads and switching contexts between the threads.