Abstract: Techniques are provided for use with implantable devices equipped with programmable voltage multipliers (including voltage dividers.) Candidate pulse widths are determined for selected voltage multipliers and stimulation vectors. Each candidate pulse width corresponds to a lowest pulse energy sufficient to achieve capture within the tissues of the patient (subject to a safety margin) using the selected vector and using the corresponding voltage multiplier. As such, a candidate pulse width represents a preferred or optimal pulse width, at least insofar as energy consumption is concerned. However, depending upon the capabilities of the device, the candidate pulse width might not be achievable. Accordingly, for each programmable vector, the system determines a lowest “operable” voltage multiplier sufficient to generate a pulse at a candidate pulse width subject to the capabilities of the device.