You're going to validate your results anyways, aren't you? Non-cryptographic random number generators are not guaranteed to introduce bias, a given implementation of a monte carlo simulation might introduce bias via a bug or a poorly chosen modeling. If you need to validate for bias anyways, so you might as well verify by checking against a cryptographic random number generator as well as whatever bias tests you may have at your disposal and then switch over for the speed.
A good non-cryptographic random number generator like xoshiro256 can generate at 4 times the speed of a chacha20 random number generator. Depending on how many models you need to compute and the desired precision of those models and how many random samples you need per model, this can easily be the difference between hours and days, or days and weeks.
A good non-cryptographic random number generator like xoshiro256 can generate at 4 times the speed of a chacha20 random number generator. Depending on how many models you need to compute and the desired precision of those models and how many random samples you need per model, this can easily be the difference between hours and days, or days and weeks.