Power supplies that are touted as the best-of-the-range models by renowned manufacturers cannot have bad results in tests. Indeed, the Antec Signature, Enermax Revolution 85+ and Seasonic M12D are free from any technical defects. These are high-wattage, well-made products with good electric parameters and quiet operation, suitable for top-end computers including configurations with two or three graphics cards. You won’t be disappointed with any of them. The only downside is that they come at an expectedly high price.
The Enermax Revolution 85+ stands out in terms of technologies. This is the first PSU tested in our labs that delivers an efficiency higher than 90%. It features an ideally balanced dual-transformer circuit capable of working at any load from zero watts, a synchronous rectifier on the +12V rail (it is the first time I see such a solution!), and dedicated DC-DC converters. Enermax’s engineers have done a good job on this product. If you are interested in power electronics and want to know how computer PSUs will develop in near future, the Revolution 85+ is a good example to study.
The two other models, Antec Signature and Seasonic M12D, are designed in a more traditional way. Instead of revolutionary innovations their developers have preferred to elaborate on well-known and long-used technologies (I have seen DC-DC converters in serial products over two years ago, for example). They cannot match the Enermax in their effective parameters but the difference is small. They are 1-3% less efficient, produce somewhat more noise under load, and do not differ at all from other aspects.
By talking so much about the circuit design of the PSUs, I wanted to emphasize two points. First, computer PSUs do not stay as they are. They evolve and improve and this development is not limited to the shape of the holes of the vent grid or the color of the fan highlighting. There emerge new controllers, some design solutions are replaced with others. There is little in common between two PSUs manufactured ten years apart, although they seem to have components of similar colors and shapes. That said, you should be reasonably skeptical about the manufacturers’ announcements of newest, recently invented and wholly patented technologies. New components only come to serially produced PSUs when they are commercially justifiable. You can take magnetic amplifiers for example. They are long used as regulators of the +3.3V rail and you can find such a regulator in every good 250W ATX power supply manufactured at the end of the last century but it is only in recent years, when the load capacity of the +12V rail has grown up greatly, that the use of two magnetic amplifiers – what is called dedicated voltage regulation – began to make sense. It’s the same with other technologies. They exist but may not be commercially reasonable until some point.
What can we expect in the near future? I guess there will be digital programmable PWM controllers whose algorithm will be adapting “on the fly” to various types of load. They exist already but are far from becoming widespread because the technology is not yet polished off and is expensive. Of course, this is just an example. There are other interesting technologies waiting to be implemented in serial products.