Result Summary

Efficiency

This supply is rated as 80 Plus Platinum; however, this will be based on the 115 V measurements. FSP do not provide an 80 Plus rating at 230 V, so we will compare the measurements to the 80 Plus Platinum (230 V) standard.


Testing at 230 V (closer to 240 V in reality), the results fall a touch short of a Platinum rating at low and mid-loads, and would come under a Gold rating. This is still a very respectable result though from a 1200 W model in this price range. Power factor is good, but not as high as we have seen on devices using more modern and sophisticated controllers.

Fan Noise

The fan blade profile coupled with the low speeds result in a wonderfully quiet experience even pushed beyond 100% load. Heavy loads were maintained for a prolonged period and the fan never ramped up beyond 1000 RPM, remaining near silent the entire time.


An interesting point worth mentioning is that during the initial test, the fan never started spinning, even at 100% load, despite the temperatures inside exceeding 100 C. The ECO switch was toggled, and the unit powered off and back on again. Only then did the fan begin spinning at around a 60% load.

Voltage Regulation

All ATX PSUs have a voltage regulation feedback loop, which increases the PWM duty cycle for each rail to account for voltage drop when current is drawn. However, most PSUs only measure voltage at the PSU output, rather than at the end of the cable going to the load. This means any voltage drop across the cable is not automatically adjusted for. The ATX 3.1 specification outlines a maximum allowed voltage drop at the load itself to ensure system stability.



Both the low-voltage rails are set a touch high but well within limits, and the 12 V rail settles to dead on 12 V by 100% load after losses across the cables. A very reasonable result.

Cable Quality

Although voltage regulation inside modern PSUs is extremely stable, voltage drop and thus power losses will occur across the cables as current is drawn through them. This results in a lower voltage available to the system components than what is actually measured at the PSU outputs. Thicker cables will cause less voltage drop and more power to the components. Any power lost across the cables is wasted as heat in the wire itself. By measuring the voltage drop at a known load, we can calculate the resistance of the cables.






The cables FSP have included have a nice low resistance with good connection quality, and quite even current sharing between cables.

Ripple

Ideally you want the DC voltage delivered by your power supply to be a completely flat line when looking through an oscilloscope. However, due to the switching nature of the ATX power supply and the less than ideal real world behaviour of all the components involved, we get very small fluctuations in the voltage output, known as ripple and noise. The ATX spec allows a ripple of up to 120 mV for the +12 V rail and 50 mV for the minor rails.



As expected given the circuit design and component choices, this is a very good ripple control result, aided by the low resistance cables.

Short Circuit Protection

Short circuit protection is one of the most fundamental and important protections for a power supply. If a short circuit is detected on any rails, the PSU should turn off and prevent damage to itself and other components.


SCP was working as expected with the unit.