The Power Window Is Important
Pegging Idle And Load Power Usage
To illustrate the next part of the analysis, we are using four PSUs as examples. These include a cheap, high-powered model from the bargain bin (the purple line), an 80 PLUS-certified PSU (blue), another 80 PLUS Bronze model (orange-brown) and finally an 80 PLUS Gold option (yellow), capable of delivering between 500W and 525W.
In the case of our super-cheap power supply, we decided to use a 750W model to ensure that it’d be able to actually reach 500W. Now, when we look at their respective efficiency curves in a given workload, we see some pretty obvious (and unpleasant) differences. Observe:
As we can see, simply buying an efficient 500W power supply is not a universal solution. To the contrary, these graphs should help us appreciate that choosing the right “size” power supply is at least as important as its quality and efficiency. You can only achieve an optimal result when all three factors are taken into consideration.