Let's say one thing up front: none of the power supplies in our comparison test blew up in a cloud of smoke under too much load. This indicates that all of the participating firms have learned from past errors - the devices shut off as they should upon overload or short circuit conditions, without any damage.

However, not every model delivered the performance that was promised. Some devices also showed voltages falling outside the specified ranges, which can result in a system crash. Usually these crashes cannot be reproduced, and everything seems to run normally again after restart. Only in the rarest of cases is the power supply diagnosed as the source of system problem. In our lab studies, however, we have often had the experience of seeing inexplicable crashing that resolved itself after exchanging the power supply.

The efficiency of many of the devices has become quite high, the leading manufacturers being Zippy and Enermax. These very same ones all deliver high performance too, and strict compliance with specifications.

In the workstation segment the products from I-Star, Zippy and Silverstone were all impressive. Silverstone's ST-52F stands out for its low price tag for an EPS power supply, Zippy is great for efficiency, and I-Star's interesting redundancy concept provides for a high level of reliability.