Android 5.0 Lollipop Encryption Found to Hamper Storage Performance by Up to 80 Percent - TechSpot
None should be surprised that strong disk encryption requires more resource, it’s a known factor that we need to take into account in all new designs. SHA 256 and up take up some computer resource, and that’s why future disks should probably build in hardware crypt/decrypt to speed these cycles and to offload the task from the main CPU. Networking DSP’s should also have hardware crypt/decrypt built in.
Android 5.0 Lollipop includes a bevy of new features and enhancements such as a remote kill switch and Trusted Places, among others. It’s also the first version of Android that enables Full Disk Encryption (FDE) by default on new devices. It’s a thoughtful gesture on Google’s part considering today’s privacy-conscious culture but as AnandTech recently discovered, it also severely hampers read / write performance.
The publication first noticed some anomalies when benchmark testing the storage system of the new Nexus 6 and decided to dig a bit deeper.
As you can see in the results above using AndEBench, FDE comes with a very significant performance penalty. With it enabled on the Nexus 6, random read performance dropped 62.9 percent while random write speeds were down 50.5 percent. The biggest hit, however, comes in the form of an 80.7 percent drop in sequential read speeds.