The Performance Impact Of Linux Disk Encryption On Ubuntu 14.04 LTS

The only thing being changed out between the Ubuntu 14.04 installs from the ASUS Zenbook Prime was the disk encryption method of the stock (no encryption), full-disk encryption, and home directory encryption.

When running the Phoronix Test Suite to facilitate this automated open-source Linux benchmarking, the MONITOR=cpu.usage environment variable was also set to record CPU usage differences while the tests were taking place.

The first test up was of PostMark and we see right away the performance hits inflicted by using disk encryption. Using the LUKS on LVM full-disk encryption was actually less of a performance hit than just using the eCryptfs-based home directory encryption. With the full-disk encryption around 20% of the performance was lost while with the home directory option the numbers were nearly at half.

When it came to the CPU usage for the Intel Core i7 Ivy Bridge ultrabook processor, the CPU usage was obviously higher when having to encrypt the information. The average CPU usage for this test was about 16% with the stock install, 25% with full-disk encryption, or 23% with home directory encryption.