A benchmark tester retrieves a voltage margin that corresponds to a device that a system includes. The voltage margin indicates an additional amount of voltage to apply to a nominal voltage that, when added, results in the device operating at a power limit while executing a worst-case power workload. Next, the benchmark tester (or thermal power management device) sets an input voltage for the device to a value equal to the sum of the voltage margin and the nominal voltage. The benchmark tester then dynamically benchmark tests the system, which includes adjusting the device's frequency and input voltage while ensuring that the device does not exceed the device's power limit. In turn, the benchmark tester records a guaranteed minimum performance boost for the system based upon a result of the benchmark testing.