fastest way to crack bcrypt

[Mem5]

hashcat64 -a 0 -m 3200 hashes.txt rockyou.txt -w 3 -O
hashcat64 -a 0 -m 3200 hashes.txt rockyou.txt -w 3 -O -d 1

-a 0 is optional here
-w 3 can be changed for -w 4 (good for headless, do not do something else while cracking)
-d 1 : why? I would suggest to use all CPUs and GPUs (if any)

And yes, bcrypt is very slow. A 2080 Ti can get around 28,640 H/s for one hash (iterations: 32). But if you have more than ~10 hashes the speed will drastically drop.