Be Quiet! Straight Power E9 680W Review

Voltage Regulation

To test voltage regulation we load the power supply to five different load scenarios that give an equal spread of load across every single rail. So that means 20% on all rails, 40% on all rails and so on. We then calculate the average deviance of each rail from its expected voltage.

The Be Quiet StraightPower E9 680W power supply had good voltage regulation on most rails though the -12 volt was quite a big let down though is forgiveable given that few components use this. 3.3 volt regulation was a bit average too.

Power Efficiency

Power efficiency is measured by calculating actual supplied wattage divided by the wattage drawn at the wall/plug, multiplied by 100 to give a percentage. We then compare that to the particular 80 Plus certification the company claims to see if it meets that. You can see the 80 Plus certifications below, we always test 230v power supplies.

The Be Quiet! Straight Power E9 conforms “on the money” to the 80 Plus Gold specifications, though with slightly higher than required 100% and 20% load efficiency.

Power Factor Correction

Power Factor Correction is the ratio of the real power flowing to the load, to the apparent power in the circuit. The aim of PFC is to make the load circuitry that is power factor corrected appear purely resistive (apparent power equal to real power). In this case, the voltage and current are in phase and the reactive power consumption is zero. The closer the number to one the better as this allows the most efficient delivery of electrical power (Source – Wikipedia).

The Be Quiet Straight Power E9 had outstanding PFC particularly from 40% load and upwards.