Conclusion
The Silverstone ST56ZF Zeus had the highest efficiency rating. With a high efficiency rating that never dips below 83%, it leads the pack, and permits only a small amount of energy to be wasted as heat. But this device suffers from excessive noise; even when only lightly loaded, noise output grates on the ears.
The ST56F Strider from the same manufacturer makes a convincing showing with its quiet operation and also offers high efficiency ratings, though it falls behind at lighter loads. Its price of about $130 is just about right for a PSU in the 560-Watt class.
The Cooler Master Real Power 550 Watt earned the single-highest overall efficiency rating. At 86.3% it outperformed any other power supply we've ever tested in the THG labs. But it dips to 79.9% efficiency at light load, and that cost its maker a first place finish. This device still suffers from a poorly designed power meter, whose small indicator makes it hard to read and only of questionable use and value.
We were pleasantly surprised by manufacturer Hiper: They fixed all their earlier failings from our live test. Today, they offer solid power supplies that follow the specifications and operate without malfunction. They must still improve on their efficiency ratings, however.
Enermax offers its first modular power supply with the ELT500AWT that also comes with power cables nicely packed inside a well-designed roll-up pouch. At a price of under $100, its buyers can take home a solid power supply with an efficiency rating of 82% at medium load (50% of rated power).
If we awarded a prize for design, Hiper would walk away with it hands-down with its Type R power supply. This power supply, with its cable management based on modular avionics-style connectors, will be sure to raise the pulse of any case modder.
