The 2019 Laptop Performance Cost To Linux Full-Disk Encryption

I certainly recommend that everyone uses full-disk encryption for their production systems, especially for laptops you may be bringing with you. In over a decade of using Linux full-disk encryption on my main systems, the overhead cost to doing so has fortunately improved with time thanks to new CPU instruction set extensions, optimizations within the Linux kernel, and faster SSD storage making the performance penalty even less noticeable. As it's been a while since my last look at the Linux storage encryption overhead, here are some fresh results using a Dell XPS laptop running Ubuntu with/without LUKS full-disk encryption.

Most Linux distributions these days make it trivial to employ full-disk encryption as part of the installation process and rely upon LUKS disk encryption though for some concerned about the performance there is also eCryptfs-based home directory encryption offered by some installers, among other options. For this round of testing I did a clean install of Ubuntu 19.04 daily without any encryption and then again when using the LUKS-based full disk encryption.

The laptop used for these fresh Linux encryption benchmarks was the Dell XPS 9370 with Intel Core i7 8550U with 2 x 4GB memory and a Samsung PM961 256GB NVMe SSD. The Ubuntu 19.04 daily snapshot of the time was running with the Linux 4.19 kernel. All of the distribution defaults were maintained during the two rounds of testing. Besides looking at the performance impact on I/O workloads, the Phoronix Test Suite was also tracking the CPU usage and battery power consumption too.