They have recently published a blog series which started with 35,000x and ended with 68,000x [1]. The thing is anyone familiar with performance sensitive code is not looking at Python vs the other thing. They are looking for whether or not it is in the ballpark of C, Julia, Cython, Numba, etc. Those are the contenders, not Python.
[1] https://www.modular.com/blog/mojo-a-journey-to-68-000x-speed...