Team Win Recovery Project has added support for native encryption on the One Plus One. This is better than Android's AOSP encryption since it is better optimized for the Qualcomm chipset. According to many benchmark tests this should offer you a 30% boost in speed and performance while encrypted. Of course if you really want your OnePlus One to be a speed deamon you will want your device completely unencrypted. This improves performance so much that Google has already indicated in code commits that it may include this in later builds of AOSP. The latest version of TWRP for the OnePlus One supports full decryption while the latest versions of CyanogenMod for the device will also support the Qualcomm Encryption.
via Google+