We've previously shared some hot tips on how to speed up the Nexus 6, but today we're sharing a slightly more severe method: disabling the Nexus 6's forced encryption. While automatic encryption is great from a security standpoint, all that encrypting and decrypting slows everything down. So now we'll show you how to speed up the Nexus 6 by disabling forced encryption.
Note: As you can probably guess, this requires replacing the existing Nexus 6 kernel with one that doesn't force encryption. You will still be able to encrypt your Nexus 6, it just isn't encrypted by default. You'll also need to wipe your data for this to work, so do a backup before you proceed. Finally, you'll need an unlocked bootloader so you can flash the kernel.
Unlocked Nexus 6. if you need help, use Boot unlocker for Nexus Devices (linked below)
2. Make sure you have USB Debugging enabled in Developer Options (if you don't have this setting yet, go to Settings > About Phone and tap Build number seven times until you see the notification that Developer options has been enabled. Now, go to Settings > Developer option and check the box for USB Debugging.)
3. Do a full backup of your Nexus 6 as this process will wipe your device.
4. Download the file below (on your PC) that corresponds to the version of Android that you are currently running. You must install the same build number or you will have problems. To see which build number you have, go to Settings > About Phone > Build Number.