Efficiency isn't associated with load in that manner and does now no longer parent in what number of watts you want in your machine see edit on the bottom, I misinterpret your question. Getting a Power Supply Unit with extra watts than you want is to get longer existence from the PSU. When you push a PSU hard (i.e. power it close to its most output) it's going to burn out quicker.
On this occasion, thanks to the small and elaborate causerie, we will be pleased to present one of them the ELECTRONIC VOLTAGE STABILIZER, and how this element, hand in hand with colorful protocols and tools of an analogous purpose, will round each other in the work of conserving the integrity of our platoon.