A timing controller for a panel display system includes: an image signal receiver that receives an image signal; an overdrive circuit that receives and converts the image signal from the image signal receiver according to successive first frame data and second frame data in the image signal; an image signal transmitter that receives the converted image signal from the overdrive circuit and transmits the same to a display panel; a memory; and a memory interface unit. In a normal read/write period, the memory interface unit receives the first frame data from the overdrive circuit and stores the same in the memory, and fetches the first frame data from the memory when the overdrive circuit receives the second frame data in the image signal and transmits the same to the overdrive circuit. The memory interface unit further obtains sampling results to generate a preferred delay phase.