[lossolo]

> Software RAID and dmcrypt will burn plenty of cycles, enough to prove as exceptions to the "no FPU instructions in the kernel" guideline.

LUKS has a negligible impact on I/O bandwidth, and the same is true for software RAID. I'm almost saturating NVMe drives using a combination of LUKS (aes-xts) and software RAID. Additionally, the encryption and decryption processes are almost free when using hardware AES-NI instructions, especially while waiting for I/O.