We get asked this quite a bit, so here is the answer.
The M140 laser we use is technically rated as a 1.6 watt (at 1.2 amps) laser diode in its specification sheets by Nichia, the manufacturer.
We run the laser at a maximum current of 1.7 amps which produces on average a little over 2 watts of laser power.
The reason we can run it at this higher power is because we are able to keep the diode cool enough not to cause it damage and our electronics help protect it from current overshoots.
The 9mm 445nm diode, which we are referring to as a 3 watt laser diode, is a similar situation. We run this at 2.4 amps maximum and achieve around 3 watts of laser power.
These performance values have been tested and if you are interested you can look at the following two links online:
Please ask for further clarification if this doesn't make sense.