The folks at HardwareLogic have taken a look at Quad-Rail power supply from "Be-Quiet" called the StraightPower 600W. As sure you can infer from the company's name that the StraightPower 600W is supposed to be a quiet PSU, but it's also supposed to be plenty powerful as well. In the end, HardwareLogic really liked this unit but wished it had a few more features to set it apart from the competition.
"Today, more than ever, we need not only great performance from our rigs, but we are also taking a stand against hellishly hot rigs that are as loud as a rock concert. Enter Be-Quiet. This company has spent the last few years building a solid reputation for themselves across Europe,for their "cool & quiet" PC parts. The StraightPower series is their fourth generation of PSUs designed to provide near silent, high-performance power with cool temps to boot. This isn't really surprising considering that they are owned by German-based Listan International, a company that owns, among others, Arctic Cooling, Cooler Master, and Zalman."