High speed rolling image sensor includes pixel array disposed in first semiconductor die, readout circuits disposed in second semiconductor die and conductors. Pixel array is partitioned into pixel sub-arrays (PSAs). Each of the PSAs includes a plurality of pixels. Pixel groups include pixels that are non-contiguous, non-overlapping and distinct. Each pixel group includes pixels from different PSAs. Each pixel group is coupled to a corresponding analog-to-digital converter and memory unit tiles (ADMs) respectively included in readout circuits. ADMs respectively include (i) analog-to-digital (ADC) circuits that convert the image data from pixel groups from analog to digital to obtain ADC outputs, and (ii) memory units to store ADC outputs. Conductors are coupling pixel array to ADMs. Conductors include number of conductors per column of pixel array. Number of conductors per column of pixel array may be equal to number of pixels in PSA arranged in same column. Other embodiments are described.