#AESni will give you at least 2GByte/s per thread & core so unless you put a pair of PCIe 5.0 x4 NVMe|s on a board with only a CPU that has 4C/8T, you shoudln't be able to measure much of a performance loss.
Espechally since that worst-case doesn't even exist AFAIK nor would it make sense.
It would be a different story if #LUKS were to use something like #RSA or other public/private asymetric crypto for the actual data encryption.


