test_load_overhead.py

import asyncio
import time


async def coro():
    await asyncio.sleep(0)

async def main(loop, coros):
    start = loop.time()
    for i in range(coros):
        await coro()
    dt = loop.time() - start
    print("Coros per second: {}".format(coros/dt))

loop = asyncio.get_event_loop()
loop.run_until_complete(main(loop, 400000))

paufreixes@ ~/pfreixes/cpython (load) $ ./python.exe ../test_load_overhead.py
Coros per second: 29601.8352714535
paufreixes@ ~/pfreixes/cpython (master) $ ./python.exe ../test_load_overhead.py
Coros per second: 30707.975008548827