Transient Testing
For those of you that are curious as to some of the reasoning and equipment behind our PSU testing program here at TheFPSReview, we have put together an introduction for you that shares a lot of the behind the scenes of the program. This program is based on what the author developed at [H]ardOCP and utilizes the equipment bequeathed to the author by Kyle Bennett. The testing we are conducting today is exactly as described in that document and will continue with our Transient Testing.
Transient Test 1
Loaded/Unloaded
12v/5v
Test #1 is equal to approximately 25% of the rated capacity of the FSP SFX PRO 450W at 45c. This makes Test #1 equal to 121W by loading the 12v rail to 8a, the 5v rail to 2a, the 3.3v rail to 1a, the +5vsb to 2a, and the -12v to 0.3a before the addition of the transient load. The results of Test #1 show a ~520mV drop on the 12v rail and ~40mV drop on the 5v rail when each is directly loaded. At the same time that the load was being triggered on the 12v rail, the 5v rail measured a ~40mV drop.
Transient Test 2
Loaded/Unloaded
12v/5v
Test #2 is equal to approximately 50% of the rated capacity of the FSP SFX PRO 450W at 45c. This makes Test #2 equal to 223W by loading the 12v rail to 16a, the 5v rail to 3a, the 3.3v rail to 2a, the +5vsb to 2a, and the -12v to 0.3a before the addition of the transient load. The results of Test #2 show a ~540mV drop on the 12v rail and ~40mV drop on the 5v rail when each is directly loaded. At the same time that the load was being triggered on the 12v rail, the 5v rail measured a ~30mV drop.
Transient Load Testing Summary
The Transient Load Tests results for the FSP SFX PRO 450W are hard to put in order. In today’s testing, the SFX PRO 450W saw the loaded 12v rail post a peak change of ~540mV, and the loaded 5v rail post a peak change of ~40mV. The unloaded 5v peak change during the 12v load was ~40mV.
Those numbers are, in an absolute sense, tolerable for a system. The 12v rail, however, started off at such a low set value that it dropped below the ATX12v/EPS specification limit. That said, we could say that this is a 450W unit and a value-oriented offering which makes these test results a lot more forgivable than they would be for a higher-end or higher capacity model. However, the Corsair CV450 (while being mixed in absolute values) never dropped below the ATX12v/EPS specification limit and it is also a lower end unit. It is not an SFX unit like this one, though. Let’s move on now to see how this unit does in the DC Output Quality aspect of our testing!