AnandTech has finished a review of the SilverStone Decathlon DA700 Super Silent power supply. This unit features a single 12V rail with 58A and should be rather silent.
The power supply is quite long for a 700W unit and after opening it up we will see why this is the case. The fan is located quite close to the back, which is unusual for power supplies as now there is a big part of the power supply inside that will not get as much direct airflow. The installed fan is 120mm, which is also common with Silverstone even though many of the competitors have changed to larger fans. The problem is that there are quite a lot of patents on larger fans and Silverstone might not want to pay royalties, especially when a 120mm fan is doing just fine.
Check it out over here. The reviewer says the DA700 delivers good quality, the voltage regulation works exceptionally well, the efficiency reaches up to 85% and the noise levels were very good.