turbo 1.2

All Turbo Levos have new motor for 2018 models. On FSR range it´s Turbo 1.3, based on new Brose Drive S, but hardtails have Turbo 1.2. Does anyone know anything about this Turbo 1.2? Is it also based on Drive S or previous Drive T? What are differences between 1.3 and 1.2, hardware or software?