Quote from: HCP on Today at 12:02:21 AM

The "library" I'm using for testing the validity of the mnemonic itself should not be too bad, it's the "to_entropy()" function from the Trezor "python-mnemonic" code: https://github.com/trezor/python-mnemonic/blob/master/mnemonic/mnemonic.py#L125

That's the problem with using a library to brute force, they are not designed to be the most efficient. They are just optimized to perform one operation in reasonable time. From a quick look this part is being repeated pointlessly and it has obvious expensive processes such as the memory lookup even if it is a binary search, the conversion between the words and bits, working with strings, unnecessary checks,...
https://github.com/trezor/python-mnemonic/blob/master/mnemonic/mnemonic.py#L126-L156

What you want to do is to first convert all your words to their binary representation without having any memory issues.
13 file * 10 word each * 4 byte to hold bits = 520 byte total
Now you create the permutation of these bits and compute their hashes. Working with integers is significantly faster than working with strings.