Phase flicker can degrade the performance of holographic applications at the device and application levels. On the device side, the meaningful phase modulation resolution is proved to be limited by the overlapping between adjacent phase levels caused by flicker. Here, the tolerance of the overlapping for different modulation levels is provided. The frame rate of the device is also constrained by the phase flicker. The balance between low flicker and fast LC response for fast frame rate is quantitatively analyzed. On the application side, the effects of real phase flicker on the performance of blazed gratings and image holograms are investigated using the temporal phase flicker profiles measured from a phase-only liquid crystal on silicon (LCOS) device; they are shown to be comparable with that introduced by quantization level and amplitude noise, respectively.