The Cost Of Home Directory Encryption & LUKS Full Disk Encryption On Ubuntu 18.04

For those that may be doing frequent and heavy code compilation tests, on this Broadwell laptop with SATA SSD, the time to compile the Linux kernel only increased very slightly to a few more seconds for this rather lengthy process. Between home encryption and full-disk encryption there was little difference in the results.

With the Compile Bench program meanwhile, using eCryptfs for the home directory encryption incurred a very significant performance penalty while the LUKS full disk encryption was very minimally impacted with this initial configuration.

But using full-disk encryption had led to a noticeably higher CPU usage during this benchmark with a ~33% vs. 44% average CPU usage and a peak of 65 vs. 76% difference.

With the actual compile test within Compile Bench, the full disk encryption overhead was a bit more noticeable but still faster than just the eCryptfs method.