It's not that a single request is 40x faster (it may be no faster), it's that 40x requests can be handled in the same amount of time. The limitation is then the

It's not that a single request is 40x faster (it may be no faster), it's that 40x requests can be handled in the same amount of time. The limitation is then the processing of the connections both in userspace and in the kernel, and the cost of all the system calls. This is easy enough to test with ab (apache bench), siege, or jmeter, by just cranking up the number of concurrent requests. I've seen 100x differences in implementations of web servers before, 40x for python vs c++ is pretty believable.