We’ve internally developed the ODROID-C3 based on the S905X2 CPU which has ARM Cortex-A53 cores almost two years ago.
But the performance was not enough and we had heard about the new coming S905X3 with modern ARM Cortex-A55 cores. Therefore, we decided to skip the ODROID-C3.
It's nice to know that instead of releasing an SBC that was only a marginal improvement, Hardkernel decided to wait and release a true step-up in performance, the ODROID-C4!