No, there is no software you could run on the system that would produce reliable, useful results. Software voltage reporting is notoriously unreliable.
You can however perform some relatively simple tests to make sure it is adequate. Just run some intensive programs to stress out the processor and video card while monitoring your main voltages (5 V, 12 V, and 3.3 V) with a multimeter. If they appear stable and in spec, you're probably all right. You can try something more complex (such as using tubing to route some of the power supply's own exhaust back to its intake), and if you have the instrumentation you can make ripple measurements, which are valuable.
It's unlikely, unless you have an absolute beast of a system, that you can even push that supply remotely close to its total maximum power rating.