We present a new volume holographic data storage architecture which consists of two photorefractive crystals storing exactly the same contents. Without a phase conjugator, the new architecture is capable of fast self enhancement of the stored gratings by using two temporally modulated plane waves. The effects of the modulation rate, reading beams′ intensity ratio, initial fixed grating strength and the crystals′ nonlinear coupling strength on the enhancement speed and steady state diffraction efficiency are discussed.