What does a task limited by input/output mean, and how does it affect system performance?

An I/O-bound task is a task whose performance mainly depends on the speed of input/output operations (disk read/write, network, peripherals) rather than on the processing resources of the CPU.

In such tasks, the processor often remains idle, waiting for I/O operations to complete. This affects system performance in the following ways:

• Increased wait time — the process cannot continue until the I/O operation finishes.
• Low CPU utilization — the processor remains idle, which can lead to inefficient resource use.
• Potential for optimization through asynchrony — using non-blocking I/O or multithreading can improve overall performance.

Example in Python using asynchronous I/O:

import asyncio

async def read_file():
    with open('file.txt', 'r') as f:
        data = await asyncio.to_thread(f.read)
    print(data)

asyncio.run(read_file())

Here, file reading is performed in a separate thread, not blocking the main execution thread.