The overall rating of a power supply is derived from combining the power available from each individual rail. In this case, there are four separate +12V rails and one of each +5, +3.3, +5, and -12V. For most of us, the +12V rails are generally the most important to look at.

      Two of the Ensemble's rails are rated for 20 Amps and the other two rails are rated at 25 Amps. Using Ohm's Law you can calculate power by multiplying the voltage times the current. P[power] = I [current] * E [voltage]. So, each of the 20 Amps rails can supply 240 watts of power and the 25 Amp rails together add another 300 watts. Adding all four rails together gives us the combined rating of 1080 watts. Knowing the amperage of the individual rails is important too because some components, primarily video cards,  demand a high amount of current. That's why some high capacity power supplies that may be rated for 1800 watts but can't supply enough amperage to feed the system - resulting in instability.

     The inside of a power supply isn't much to look at. Just a bunch of wires, inductors, capacitors, and really big heat sinks on the voltage rectifiers. To most of us, it isn't important that the larger capacitors and inductors greatly help to ensure the square wave produced by the step-down transformers and the line regulators gets leveled off to a solid-line of Direct Current voltage. Most of us just want the PC to go beep when we hit the power button. It just so happens that this one component with its hundreds of sub-components is directly responsible for that.

     You'll have to keep in mind that the Ensemble is not a modular power supply, so all of the connectors you don't use will have to be stowed. Sure it's got Molex and floppy style connectors, but here's a quick look at the really important ones....