Take Drive at full dose on both workout and non-workout days.
Take RPM daily, too. Take a full dose on workout days, and a half-dose on non-workout days. This way, like the earlier contributors said, you would maintain high cellular concentrations of the actives in both products, ensuring effective cumulative results. As long as you dose Drive at full dose, there will be no disadvantage of dosing RPM at half-dose on non-workout days, as the synergy between Drive and RPM would ensure the effectiveness of RPM does not diminish in any way.