Ubuntu 11.10 Home Encryption Performance

Strangely, for the Threaded I/O Tester was run and doing eight threads of 64MB random writes, an encrypted home directory had actually boosted the performance by 6% compared to the stock installation. For the Core 2 Duo netbook, the performance on the encrypted home directory had fallen, this time it was at a loss by about 11%.

On the new Intel Sandy Bridge notebook backed by a high-performance solid-state drive, the impact of using an encrypted home directory in Ubuntu 11.10 was negligible. For the older Intel Core 2 Duo notebook with a hard-drive, the impact in disk-centric workloads varied from 10~20%. However, most people are concerned about using a web-browser and other applications on their mobile systems rather than running mail servers or multi-threaded disk writes, in which situation for normal usage the difference should be minimal.

While I am often after peak Linux performance, when it comes to disk encryption, I feel the cost is certainly justified and recommend it to any mobile user. In particular, using full-disk encryption where there is data of any importance.

Coming up when Ubuntu 11.10 is officially released (and the alternate installer hopefully back to working for encrypted LVMs) will be more disk encryption benchmarks with a wider variety of Intel netbooks/notebooks (sorry, there hasn't been any AMD mobile devices supplied to Phoronix) to see the impact of both disk encryption methods. Those tests will also include looking at how the CPU usage and power consumption are affected.

Those looking to compare or play with these disk encryption results can find them on OpenBenchmarking.org as 1108245-LI-1108242LI98.