Summarizing the results of my tests I have no doubts about the best performers – they are the models from OCZ Technology. These are well-made units capable of supplying good power to any computer system existing or likely to appear in the next couple of years.
Antec’s unit isn’t inferior to OCZ’s products in the design, but it belongs to the relatively old TruePower series that doesn’t comply with the perspective ATX12V 2.0 standard. Unfortunately, we don’t yet have units from the new NeoPower series that would make a tougher competitor to OCZ’s PSUs. The reviewed Antec will suit nicely for today’s systems, but if you want your PSU to be future-proof, consider either Antec’s NeoPower line or the above-described OCZ PowerStream series.
The BeQuiet P4-450W model was a disappointment. Yes, it is a high-quality PSU with good parameters but its characteristics lack luster against the models from Antec and OCZ. The competitors have a much better stability of the output voltages, so the cross-load characteristics of the P4-450W look pale in comparison. This PSU couldn’t also meet our expectations as concerns the noise. The soft buzz of its fan makes it no less quiet than the models from OCZ, but OCZ’s PSUs have much better other parameters.
Overall, we see that the PSU manufacturers have managed to develop truly universal models that comply with all the existing standards by using the independent regulation of the output voltages. Moreover, even within the requirements of a particular standard these models surpass their competitors in the stability of the voltages, so this is not a marketing trick or beautiful words on the label, but a very useful innovation. The apprehensions that the additional regulators would reduce the efficiency of the PSU didn’t prove true as the magnetic amplifiers themselves have a good efficiency factor. In my today’s tests the classic-scheme PSU had the worst efficiency, so you should agree that the efficiency depends more on the design features of a unit rather than on the presence of an additional output regulator.
Of course, such power supplies are rather expensive today, but I wouldn’t call their price sky-high. Units of the same wattage, but made by the classic scheme, have cost the same money, if not even more, quite recently.