f you are ONLY validating the checksum of each permutation then your speed must be in the millions per second rate. 10k is way too low for that because essentially you are just computing SHA256 (for BIP39) or SHA512 (for Electrum) and your CPU is capable of computing millions per second of these hashes.
Which would probably be true if you had a pre-existing list of all the seed word permutations and/or seed value...
But I ran into memory issues attempting to pre-compute everything, so it has to generate each permutation, then attempt to convert it to a seed while checking the checksum etc... I'm sure the way the algorithm is generating the seed permuations is probably pretty poor. It's basically just iterating some lists.
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#L125But I'm sure there are probably ways to make that more efficient.