Compared to pcDuino v2, pcDuino3 is bigger, and equipped with more interfaces.
The most significant change is the processor. pcDuino3 uses a Allwinner A20 Dual Core 1.5GHz ARM Cortex A7. Another significant change is the SATA host interface. Now pcDuino3 can accommodate hard disk drivers, wheres this is only possible through an external USB drive on pcDuino v2.
The following screen shot shows a 500GB hard drive mounted on pcDuino3: