Sony Xperia SP is powered by a dual-core Snapdragon processor with a 1.7 GHz clock speed per core. The Xperia SP uses a 4.6″ screen with a 720p resolution. Sony has implemented the Mobile Bravia Engine 2 into the phone, which helps to create the “Reality Display” that Sony has used in advertisements for the SP. The Sony Xperia SP has an 8 MP rear camera that is capable of recording 1080p. The camera is also capable of a digital zoom up to 16x.
CyanogenMod team have released the official CM 12.1 nightly for a glut of Sony devices. Xperia SP is among them. Sony Xperia SP wont be receiving official Android 5.1.1 update. So you can update it to Android 5.1.1 using the CM 12.1 custom ROM. Follow the guide below.