Lollipop encryption feature has significant performance penalty
We had spoken earlier about the sweetness of Android 5.0 Lollipop just after it was released officially by Google. One of the most important and main feature of Android 5.0 Lollipop is encryption. Encryption on Android 5.0 Lollipop encrypts all your data and can only be decrypted when you unlock the phone using the passcode which technically makes it unusable to someone without the passcode even if they are able to access the memory. Below you can view the Internal NAND – Random Read test, the Random Write test and the Sequential Read test.
Devices like the Nexus 5 which for the Android Lollipop update have the encryption feature disabled by default has to be enabled separately. The Nexus 6 and the Nexus 9 come with it enabled by default and it cannot be disabled. AnandTech has some tests shown that the encryption feature has a severe performance penalty.
A couple of benchmarks on the standard Nexus 6 and a special version by Motorola were tried with the encryption disabled. As can be seen above in each of the tests, the Nexus 6 with encryption disabled was faster than the standard version. The same test was repeated on the Nexus 5 and the performance was greatly reduced after enabling the feature.