A motorized, manual fed cassava root chipping machine was developed, evaluated and optimized. The objective of the research is to investigate the effect of moisture content and speed on the chipping sizes, efficiency, throughput and machine capacities. Obtained results showed that the cassava initial moisture content significantly affected the chipping size, machine capacity, throughput capacity and chipping efficiency within the tested moisture content range of 52 to 68% w.b. The machine speed also affected the chipping size, chipping efficiency, machine and throughput capacity. The average chipping size for the cassava chips at the four ranges of moisture content, speeds and constant feed rate of 89±26.6 kg h-1 ranged from 0.56 to 0.96 cm with optimum thickness 0.618 at 450 rpm and moisture content of 65.27% based on desirability factor. The average chipping efficiency ranged from 60 to 90% with an optimum value of 79.57% at 533 rpm and moisture content of 68 % while the throughput capacities of the machine ranged from 49 to118 kg/h with optimum value of 118 kg/h at a speed of 600 rpm and 68% moisture content.