Google Android 5.0 Lollipop security discovered to limit storage space functionality by 80 percent

Google Android 5.0 Lollipop comprises of a multitude new features and improvements such as a remote kill switch and Trusted Places, and It’s also the first Google Android device that enables Full Disk Encryption (FDE) by default on new android devices. It’s a thoughtful gesture on Google’s part considering today’s privacy-aware culture but as discovered by AnandTech recently, it also severely hinders read / write performance.
Some irregularities was first noticed by the publication, 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, Full Disk Encryption (FDE) comes with a very major 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.
 
It’s worth pointing out that the Nexus 5 in their testing was running Android 4.4 then upgraded to Lollipop. When a user upgrades an older device to Lollipop, Full Disk Encryption (FDE) don’t turned on automatically – such is only the case on new devices that ship with Google Android 5.0 Lollipop.
For those who are curious, Full Disc Encryption (FDE) has been available since Google Android 3.0 Honeycomb but again, Lollipop is the first Google android os build to enable it by default on new devices.



The results nearly look deep but it does make sense. With Full Disk Encryption (FDE) enabled, all writes to disk are encrypted before being saved and equally, all reads are decrypted before being sent to Random Access Memory (RAM).
What makes things worse is the fact that the key to decrypt is protected by the device lockscreen password. That means those who don’t use a passcode on their device lockscreen are taking the performance hit without any advantages from Full Disk Encryption (FDE).
With any luck, Google will find a workaround to speed up Full Disk Encryption (FDE) reads and writes though given that it’s been around since Google Android 3.0 Honeycomb (2011), it seems somewhat unlikely. At the very least, maybe they will reconsider whether it should be enabled by default or not.
If your Nexus 6 feels a bit flaggy at times, this could be the reason. It may be worth turning of the Full Disk Encryption (FDE) for a bit to see if it helps increase the performance of the device. For now, however, users must decide if the added security is worth the performance trade-off.