DV Hardware today took a look at the ToughPower 550 Watt power supply from ThermalTake. This NVIDIA SLI and ATI CrossFire ready PSU features independent voltage circuits and promises a voltage regulation of less than 3 percent. The PSU has a black cover and features a large 120mm fan to provide quiet cooling. Read on to see how this PSU performs on an overclocked AMD Opteron 148 based rig running at 3GHz.