Bench mark Python 3.13 w/ and w/o GIL enabled.

benchmark.py

import time
import multiprocessing
import threading
from concurrent.futures import ThreadPoolExecutor


def cpu_bound_task(n):
    """A CPU-bound task that calculates the sum of squares."""
    return sum(i * i for i in range(n))


def run_sequential(numbers):
    """Run the task sequentially."""
    return [cpu_bound_task(num) for num in numbers]


def run_multiprocessing(numbers):
    """Run the task using multiprocessing."""
    with multiprocessing.Pool() as pool:
        return pool.map(cpu_bound_task, numbers)


def run_threading(numbers):
    """Run the task using threading."""
    with ThreadPoolExecutor() as executor:
        return list(executor.map(cpu_bound_task, numbers))


if __name__ == "__main__":
    # Input: list of numbers to process
    numbers = [10_000_000 + x for x in range(20)]

    # Sequential approach
    start_time = time.perf_counter()
    sequential_result = run_sequential(numbers)
    sequential_time = time.perf_counter() - start_time

    # Multiprocessing approach
    start_time = time.perf_counter()
    multiprocessing_result = run_multiprocessing(numbers)
    multiprocessing_time = time.perf_counter() - start_time

    # Threading approach
    start_time = time.perf_counter()
    threading_result = run_threading(numbers)
    threading_time = time.perf_counter() - start_time

    # Print results
    print(f"Sequential time: {sequential_time:.2f} seconds")
    print(f"Threading time: {threading_time:.2f} seconds")
    print(f"Multiprocessing time: {multiprocessing_time:.2f} seconds")
    print(f"Threading speedup: {sequential_time / threading_time:.2f}x")
    print(f"Multiprocessing speedup: {sequential_time / multiprocessing_time:.2f}x")

    # Verify results are the same
    assert (
        sequential_result == multiprocessing_result == threading_result
    ), "Results do not match!"
    print("Results verified: all approaches produce the same output.")

Here's my result using Python 3.13.0rc3 vs Python 3.13.0rc3t

% python ex.py
Sequential time: 9.88 seconds
Threading time: 9.96 seconds
Multiprocessing time: 2.45 seconds
Threading speedup: 0.99x
Multiprocessing speedup: 4.03x
Results verified: all approaches produce the same output.

~ took 22s
% pyenv local 3.13.0rc3t

~
% python -VV            
Python 3.13.0rc3 experimental free-threading build (main, Oct 12 2024, 20:39:40) [Clang 16.0.0 (clang-1600.0.26.3)]

~
% python ex.py          
Sequential time: 10.31 seconds
Threading time: 2.43 seconds
Multiprocessing time: 2.37 seconds
Threading speedup: 4.25x
Multiprocessing speedup: 4.36x
Results verified: all approaches produce the same output.

~ took 15s